Signaling of delta configuration for handover

ABSTRACT

A delta configuration is signaled for handover of a wireless communication device (e.g., a user equipment, UE) from a first form of connectivity to a second form of connectivity. For example, a UE with master cell group (MCG) connectivity may be handed-over to multiple radio access technology-dual connectivity (MR-DC). In some examples, a UE with standalone (SA) connectivity may be handed-over to non-standalone (NSA) connectivity (e.g., dual connectivity). In conjunction with this handover the UE may be signaled as to whether the UE is to reuse a configuration from the first connectivity mode during the second connectivity mode.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application for patent claims priority to and the benefit ofU.S. Provisional Application No. 62/972,575, titled “SIGNALING OF DELTACONFIGURATION FOR HANDOVER” filed Feb. 10, 2020, and assigned to theassignee hereof and hereby expressly incorporated by reference herein asif fully set forth below in its entirety and for all applicablepurposes.

TECHNICAL FIELD

The technology discussed below generally relates to wirelesscommunication and, more particularly but not exclusively, to signaling adelta configuration for handover of a wireless communication device.

INTRODUCTION

A wireless communication network may be deployed over a definedgeographical area to provide various types of services (e.g., voice,data, multimedia services, etc.) to users within that geographical area.In a typical implementation, base stations (e.g., corresponding todifferent cells) are distributed throughout a network to providewireless connectivity for user equipment (e.g., cell phones) operatingwithin the geographical area served by the network.

At a given point in time, a user equipment (UE) may be served by a givenone of these base stations. As the UE roams throughout the geographicalarea, the UE may move away from its serving base station and move closerto another base station. In addition, signal conditions within a givencell may change, whereby a UE terminal may be better served by anotherbase station. In these cases, to maintain mobility for the UE, the UEmay be handed-over from its serving base station to another basestation.

SUMMARY

The following presents a summary of one or more aspects of the presentdisclosure, in order to provide a basic understanding of such aspects.This summary is not an extensive overview of all contemplated featuresof the disclosure and is intended neither to identify key or criticalelements of all aspects of the disclosure nor to delineate the scope ofany or all aspects of the disclosure. Its sole purpose is to presentsome concepts of one or more aspects of the disclosure in a form as aprelude to the more detailed description that is presented later.

In one example, a method for wireless communication at a wirelesscommunication device (e.g., a UE) is disclosed. The method includesusing a source configuration for master cell group (MCG) connectivity,receiving a message associated with handover of the wirelesscommunication device from the MCG connectivity to multiple radio accesstechnology-dual connectivity (MR-DC), determining that the message doesnot include a full configuration indication, and configuring a secondarycell group (SCG) configuration for the MR-DC by reusing the sourceconfiguration as a result of the determining that the message does notinclude the full configuration indication.

Another example provides a wireless communication device (e.g., a UE)for a wireless communication network. The user equipment includes atransceiver configured to communicate with a radio access network, amemory, and a processor coupled to the transceiver and the memory. Theprocessor and the memory are configured to use a source configurationfor master cell group connectivity, receive a message associated withhandover of the wireless communication device from the MCG connectivityto multiple radio access technology-dual connectivity (MR-DC), determinethat the message does not include a full configuration indication, andconfigure a secondary cell group (SCG) configuration for the MR-DC byreusing the source configuration as a result of the determination thatthe message does not include the full configuration indication.

Another example provides a wireless communication device (e.g., a UE)for a wireless communication network. The wireless communication deviceincludes means for using a source configuration for master cell groupconnectivity, means for receiving a message associated with handover ofthe wireless communication device from the MCG connectivity to multipleradio access technology-dual connectivity (MR-DC), means for determiningthat the message does not include a full configuration indication, andmeans for configuring a secondary cell group (SCG) configuration for theMR-DC by reusing the source configuration as a result of the determiningthat the message does not include the full configuration indication.

Another example provides an article of manufacture for use by a wirelesscommunication device (e.g., a UE) in a wireless communication network.The article of manufacture includes a computer-readable medium havingstored therein instructions executable by one or more processors of thewireless communication device to use a source configuration for mastercell group connectivity, receive a message associated with handover ofthe wireless communication device from the MCG connectivity to multipleradio access technology-dual connectivity (MR-DC), determine that themessage does not include a full configuration indication, and configurea secondary cell group (SCG) configuration for the MR-DC by reusing thesource configuration as a result of the determination that the messagedoes not include the full configuration indication.

Another example provides a method for wireless communication at awireless communication device (e.g., a UE). The method includesreceiving a message associated with handover of the wirelesscommunication device from a first connectivity mode to a secondconnectivity mode. At least one of the first connectivity mode or thesecond connectivity mode is a multi-connectivity mode. The methodfurther includes determining that the message indicates that thewireless communication device is to reuse a first configurationassociated with the first connectivity mode for the second connectivitymode, and obtaining a second configuration for the second connectivitymode based on the first configuration as a result of the determiningthat the message indicates that the wireless communication device is toreuse the first configuration.

Another example provides a wireless communication device (e.g., a UE)for a wireless communication network. The user equipment includes atransceiver configured to communicate with a radio access network, amemory, and a processor coupled to the transceiver and the memory. Theprocessor and the memory are configured to receive a message associatedwith handover of the wireless communication device from a firstconnectivity mode to a second connectivity mode. At least one of thefirst connectivity mode or the second connectivity mode is amulti-connectivity mode. The processor and the memory are furtherconfigured to determine that the message indicates that the wirelesscommunication device is to reuse a first configuration associated withthe first connectivity mode for the second connectivity mode, and obtaina second configuration for the second connectivity mode based on thefirst configuration as a result of the determination that the messageindicates that the wireless communication device is to reuse the firstconfiguration.

Another example provides a wireless communication device (e.g., a UE)for a wireless communication network. The device includes means forreceiving a message associated with handover of the wirelesscommunication device from a first connectivity mode to a secondconnectivity mode. At least one of the first connectivity mode or thesecond connectivity mode is a multi-connectivity mode. The apparatusfurther includes means for determining that the message indicates thatthe wireless communication device is to reuse a first configurationassociated with the first connectivity mode for the second connectivitymode, and means for obtaining a second configuration for the secondconnectivity mode based on the first configuration as a result of thedetermining that the message indicates that the wireless communicationdevice is to reuse the first configuration.

Another example provides an article of manufacture for use by a wirelesscommunication device (e.g., a UE) in a wireless communication network.The article of manufacture includes a computer-readable medium havingstored therein instructions executable by one or more processors of thewireless communication device to receive a message associated withhandover of the wireless communication device from a first connectivitymode to a second connectivity mode. At least one of the firstconnectivity mode or the second connectivity mode is amulti-connectivity mode. The computer-readable medium also has storedtherein instructions executable by one or more processors of thewireless communication device to determine that the message indicatesthat the wireless communication device is to reuse a first configurationassociated with the first connectivity mode for the second connectivitymode, and obtain a second configuration for the second connectivity modebased on the first configuration as a result of the determination thatthe message indicates that the wireless communication device is to reusethe first configuration.

Another example provides a method for wireless communication at a basestation. The method includes determining that a wireless communicationdevice (e.g., a UE) is to be handed-over from master cell groupconnectivity to multiple radio access technology-dual connectivity(MR-DC), generating a message as a result of the determination, andsending the message to the wireless communication device. The messageindicates whether delta signaling is applicable to a secondary cellgroup (SCG) configuration for the MR-DC.

Another example provides a base station that includes a processor, atransceiver, and a memory that are communicatively coupled to oneanother. The processor and the memory are configured to determine that awireless communication device (e.g., a UE) is to be handed-over frommaster cell group connectivity to multiple radio access technology-dualconnectivity (MR-DC), generate a message as a result of thedetermination, and send the message to the wireless communicationdevice. The message indicates whether delta signaling is applicable to asecondary cell group (SCG) configuration for the MR-DC.

Another example provides a base station. The base station includes meansfor determining that a wireless communication device (e.g., a UE) is tobe handed-over from master cell group connectivity to multiple radioaccess technology-dual connectivity (MR-DC), means for generating amessage as a result of the determination, and means for sending themessage to the wireless communication device. The message indicateswhether delta signaling is applicable to a secondary cell group (SCG)configuration for the MR-DC.

Another example provides an article of manufacture for use by a basestation in a wireless communication network. The article of manufactureincludes a computer-readable medium having stored therein instructionsexecutable by one or more processors of the base station to determinethat a wireless communication device (e.g., a UE) is to be handed-overfrom master cell group connectivity to multiple radio accesstechnology-dual connectivity (MR-DC), generate a message as a result ofthe determination, and send the message to the wireless communicationdevice. The message indicates whether delta signaling is applicable to asecondary cell group (SCG) configuration for the MR-DC.

Another example provides a method of communication for an apparatus. Themethod includes determining that a wireless communication device (e.g.,a UE) is to be handed-over from a first connectivity mode to a secondconnectivity mode. At least one of the first connectivity mode or thesecond connectivity mode is a multi-connectivity mode. The methodfurther includes generating a message as a result of the determination.The message includes an indication of whether the wireless communicationdevice is to reuse a configuration associated with the firstconnectivity mode for the second connectivity mode. The method furtherincludes sending the message to the wireless communication device.

Another example provides an apparatus that includes a processor, atransceiver, and a memory that are communicatively coupled to oneanother. The processor and the memory are configured to determine that awireless communication device (e.g., a UE) is to be handed-over from afirst connectivity mode to a second connectivity mode. At least one ofthe first connectivity mode or the second connectivity mode is amulti-connectivity mode. The processor and the memory are furtherconfigured to generate a message as a result of the determination. Themessage includes an indication of whether the wireless communicationdevice is to reuse a configuration associated with the firstconnectivity mode for the second connectivity mode. The processor andthe memory are further configured to send the message to the wirelesscommunication device.

Another example provides an apparatus. The apparatus includes means fordetermining that a wireless communication device (e.g., a UE) is to behanded-over from a first connectivity mode to a second connectivitymode. At least one of the first connectivity mode or the secondconnectivity mode is a multi-connectivity mode. The apparatus furtherincludes means for generating a message as a result of thedetermination. The message includes an indication of whether thewireless communication device is to reuse a configuration associatedwith the first connectivity mode for the second connectivity mode. Theapparatus further includes means for sending the message to the wirelesscommunication device.

Another example provides an article of manufacture for use by anapparatus in a wireless communication network. The article ofmanufacture includes a computer-readable medium having stored thereininstructions executable by one or more processors of the apparatus todetermine that a wireless communication device (e.g., a UE) is to behanded-over from a first connectivity mode to a second connectivitymode. At least one of the first connectivity mode or the secondconnectivity mode is a multi-connectivity mode. The computer-readablemedium also has stored therein instructions executable by one or moreprocessors of the wireless communication device to generate a message asa result of the determination. The message includes an indication ofwhether the wireless communication device is to reuse a configurationassociated with the first connectivity mode for the second connectivitymode. The computer-readable medium also has stored therein instructionsexecutable by one or more processors of the wireless communicationdevice to send the message to the wireless communication device.

These and other aspects of the disclosure will become more fullyunderstood upon a review of the detailed description, which follows.Other aspects, features, and implementations of the disclosure willbecome apparent to those of ordinary skill in the art, upon reviewingthe following description of specific implementations of the disclosurein conjunction with the accompanying figures. While features of thedisclosure may be discussed relative to certain implementations andfigures below, all implementations of the disclosure can include one ormore of the advantageous features discussed herein. In other words,while one or more implementations may be discussed as having certainadvantageous features, one or more of such features may also be used inaccordance with the various implementations of the disclosure discussedherein. In similar fashion, while certain implementations may bediscussed below as device, system, or method implementations it shouldbe understood that such implementations can be implemented in variousdevices, systems, and methods.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of a wireless communication systemaccording to some aspects

FIG. 2 is a conceptual illustration of an example of a radio accessnetwork according to some aspects.

FIG. 3 is a schematic illustration of an example of wireless resourcesin an air interface utilizing orthogonal frequency divisionalmultiplexing (OFDM) according to some aspects.

FIG. 4 is a diagram illustrating an example of standalone (SA) tonon-standalone (NSA) handover.

FIG. 5 is a message flow diagram illustrating an example of SA to NSAhandover according to some aspects.

FIG. 6 is a message flow diagram illustrating an example of SA toE-UTRAN NR-dual connectivity (EN-DC) handover according to some aspects.

FIG. 7 is a block diagram illustrating a wireless communication systemthat uses delta signaling according to some aspects.

FIG. 8 is a flow diagram illustrating an example of standalone New Radio(NR) to NR dual connectivity (NR-DC) handover according to some aspects.

FIG. 9 is a flow diagram illustrating an example of standalone LTE toLTE-DC handover according to some aspects.

FIG. 10 is a flow diagram illustrating an example of EN-DC to standaloneNR handover according to some aspects.

FIG. 11 is a flow diagram illustrating an example of standalone EN-DC toNR-DC handover according to some aspects.

FIG. 12 is a block diagram illustrating an example of a hardwareimplementation for a user equipment employing a processing systemaccording to some aspects.

FIG. 13 is a flowchart illustrating an example of a handover processusing delta signaling for handover according to some aspects.

FIG. 14 is a flowchart illustrating an example of a process for deltasignaling for multi-connectivity handover according to some aspects.

FIG. 15 is a block diagram illustrating an example of a hardwareimplementation for a base station employing a processing systemaccording to some aspects.

FIG. 16 is a flowchart illustrating an example of a handover processusing delta signaling according to some aspects.

FIG. 17 is a flowchart illustrating an example of a process for deltasignaling for multi-connectivity handover according to some aspects.

FIG. 18 is a block diagram conceptually illustrating an example hardwareimplementation of a device for wireless communication (e.g., a UE)according to some aspects.

FIG. 19 is a block diagram conceptually illustrating another examplehardware implementation of a device for wireless communication (e.g., aUE) according to some aspects.

FIG. 20 is a block diagram conceptually illustrating an example hardwareimplementation of a device for wireless communication (e.g., a basestation) according to some aspects.

FIG. 21 is a block diagram conceptually illustrating another examplehardware implementation of a device for wireless communication (e.g., abase station) according to some aspects.

DETAILED DESCRIPTION

The detailed description set forth below in connection with the appendeddrawings is intended as a description of various configurations and isnot intended to represent the only configurations in which the conceptsdescribed herein may be practiced. The detailed description includesspecific details for the purpose of providing a thorough understandingof various concepts. However, it will be apparent to those skilled inthe art that these concepts may be practiced without these specificdetails. In some instances, well known structures and components areshown in block diagram form to avoid obscuring such concepts.

While aspects and examples are described in this application byillustration to some examples, those skilled in the art will understandthat additional implementations and use cases may come about in manydifferent arrangements and scenarios. Innovations described herein maybe implemented across many differing platform types, devices, systems,shapes, sizes, packaging arrangements. For example, examples and/or usesmay come about via integrated chip examples and othernon-module-component based devices (e.g., end-user devices, vehicles,communication devices, computing devices, industrial equipment,retail/purchasing devices, medical devices, artificialintelligence-enabled devices, etc.). While some examples may or may notbe specifically directed to use cases or applications, a wide assortmentof applicability of described innovations may occur. Implementations mayrange a spectrum from chip-level or modular components to non-modular,non-chip-level implementations and further to aggregate, distributed, orOEM devices or systems incorporating one or more aspects of thedescribed innovations. In some practical settings, devices incorporatingdescribed aspects and features may also necessarily include additionalcomponents and features for implementation and practice of claimed anddescribed examples. For example, transmission and reception of wirelesssignals necessarily includes a number of components for analog anddigital purposes (e.g., hardware components including antenna,RF-chains, power amplifiers, modulators, buffer, processor(s),interleaver, adders/summers, etc.). It is intended that innovationsdescribed herein may be practiced in a wide variety of devices,chip-level components, systems, distributed arrangements, end-userdevices, etc., of varying sizes, shapes and constitution.

Various aspects of the disclosure relate to signaling a deltaconfiguration in conjunction with handover of a wireless communicationdevice (e.g., a user equipment, UE) from one form of connectivity toanother. For example, a UE with master cell group (MCG) connectivity maybe handed-over to multiple radio access technology-dual connectivity(MR-DC). In conjunction with this handover the UE may be signaled as towhether the UE is to reuse a configuration from the first connectivitymode during the second connectivity mode. In some examples, a UE withstandalone (SA) connectivity may be handed-over to non-standalone (NSA)connectivity (e.g., dual connectivity). In conjunction with thishandover, the UE may be signaled as to whether the UE is to reuse aconfiguration from SA during NSA.

The various concepts presented throughout this disclosure may beimplemented across a broad variety of telecommunication systems, networkarchitectures, and communication standards. Referring now to FIG. 1, asan illustrative example without limitation, various aspects of thepresent disclosure are illustrated with reference to a wirelesscommunication system 100. The wireless communication system 100 includesthree interacting domains: a core network 102, a radio access network(RAN) 104, and at least one scheduled entity 106. The at least onescheduled entity 106 may be referred to as a user equipment (UE) 106 inthe discussion that follows. The RAN 104 includes at least onescheduling entity 108. The at least one scheduling entity 108 may bereferred to as a base station (BS) 108 in the discussion that follows.By virtue of the wireless communication system 100, the UE 106 may beenabled to carry out data communication with an external data network110, such as (but not limited to) the Internet.

In some examples, the RAN 104 (e.g., a base station 108) may beconfigured to signal a delta configuration for handover 122. Forexample, the base station 108 may indicate to the UE 106 via a messagewhether a configuration used by the UE at a source node is to be reusedat a target node. The base station 108 may further be configured toperform other operations related to the handover.

In some examples, the UE 106 may be configured to determine whether toreuse a configuration for handover 124. In some aspects, thisdetermination may be based on a signaled delta configuration (e.g.,received in a message). For example, the UE 106 may reuse at least oneconfiguration (that the UE used at a source cell) when connecting with atarget cell for the handover. These and other aspects of configuring aUE for handover are described in more detail after the description ofthe wireless communication system 100 that follows.

The RAN 104 may implement any suitable wireless communication technologyor technologies to provide radio access to the UE 106. As one example,the RAN 104 may operate according to 3rd Generation Partnership Project(3GPP) New Radio (NR) specifications, often referred to as 5G. Asanother example, the RAN 104 may operate under a hybrid of 5G NR andEvolved Universal Terrestrial Radio Access Network (eUTRAN) standards,often referred to as LTE. The 3GPP refers to this hybrid RAN as anext-generation RAN, or NG-RAN. Of course, many other examples may beutilized within the scope of the present disclosure.

As illustrated, the RAN 104 includes a plurality of base stations 108.Broadly, a base station is a network element in a radio access networkresponsible for radio transmission and reception in one or more cells toor from a UE. In different technologies, standards, or contexts, a basestation may variously be referred to by those skilled in the art as abase transceiver station (BTS), a radio base station, a radiotransceiver, a transceiver function, a basic service set (BSS), anextended service set (ESS), an access point (AP), a Node B (NB), aneNode B (eNB), a gNode B (gNB), a transmission and reception point(TRP), or some other suitable terminology. In some examples, a basestation may include two or more TRPs that may be co-located ornon-co-located. The TRPs may communicate on the same carrier frequencyor different carrier frequencies within the same frequency band ordifferent frequency bands.

The radio access network 104 is further illustrated supporting wirelesscommunication for multiple mobile apparatuses. A mobile apparatus may bereferred to as user equipment (UE) in 3GPP standards, but may also bereferred to by those skilled in the art as a mobile station (MS), asubscriber station, a mobile unit, a subscriber unit, a wireless unit, aremote unit, a mobile device, a wireless device, a wirelesscommunications device, a remote device, a mobile subscriber station, anaccess terminal (AT), a mobile terminal, a wireless terminal, a remoteterminal, a handset, a terminal, a user agent, a mobile client, aclient, or some other suitable terminology. A UE may be an apparatusthat provides a user with access to network services. In examples wherethe RAN 104 operates according to both the LTE and 5G NR standards, theUE 106 may be an Evolved-Universal Terrestrial Radio Access Network(E-UTRAN)-New Radio dual connectivity (NR DC) UE (i.e., an EN-DC UE)that is capable of simultaneously connecting to an LTE base station anda NR base station to receive data packets from both the LTE base stationand the NR base station.

Within the present document, a “mobile” apparatus need not necessarilyhave a capability to move, and may be stationary. The term mobileapparatus or mobile device broadly refers to a diverse array of devicesand technologies. UEs may include a number of hardware structuralcomponents sized, shaped, and arranged to help in communication; suchcomponents can include antennas, antenna arrays, RF chains, amplifiers,one or more processors, etc. electrically coupled to each other. Forexample, some non-limiting examples of a mobile apparatus include amobile, a cellular (cell) phone, a smart phone, a session initiationprotocol (SIP) phone, a laptop, a personal computer (PC), a notebook, anetbook, a smartbook, a tablet, a personal digital assistant (PDA), anda broad array of embedded systems, e.g., corresponding to an “Internetof Things” (IoT). A mobile apparatus may additionally be an automotiveor other transportation vehicle, a remote sensor or actuator, a robot orrobotics device, a satellite radio, a global positioning system (GPS)device, an object tracking device, a drone, a multi-copter, aquad-copter, a remote control device, a consumer and/or wearable device,such as eyewear, a wearable camera, a virtual reality device, a smartwatch, a health or fitness tracker, a digital audio player (e.g., MP3player), a camera, a game console, etc. A mobile apparatus mayadditionally be a digital home or smart home device such as a homeaudio, video, and/or multimedia device, an appliance, a vending machine,intelligent lighting, a home security system, a smart meter, etc. Amobile apparatus may additionally be a smart energy device, a securitydevice, a solar panel or solar array, a municipal infrastructure devicecontrolling electric power (e.g., a smart grid), lighting, water, etc.,an industrial automation and enterprise device, a logistics controller,agricultural equipment, etc. Still further, a mobile apparatus mayprovide for connected medicine or telemedicine support, i.e., healthcare at a distance. Telehealth devices may include telehealth monitoringdevices and telehealth administration devices, whose communication maybe given preferential treatment or prioritized access over other typesof information, e.g., in terms of prioritized access for transport ofcritical service data, and/or relevant QoS for transport of criticalservice data.

Wireless communication between a RAN 104 and a UE 106 may be describedas utilizing an air interface. Transmissions over the air interface froma base station (e.g., base station 108) to one or more UEs (e.g., UE106) may be referred to as downlink (DL) transmission. In some examples,the term downlink may refer to a point-to-multipoint transmissionoriginating at a scheduling entity (described further below; e.g., basestation 108). Another way to describe this point-to-multipointtransmission scheme may be to use the term broadcast channelmultiplexing. Transmissions from a UE (e.g., UE 106) to a base station(e.g., base station 108) may be referred to as uplink (UL)transmissions. In some examples, the term uplink may refer to apoint-to-point transmission originating at a scheduled entity (describedfurther below; e.g., UE 106).

In some examples, access to the air interface may be scheduled, whereina scheduling entity (e.g., a base station 108) allocates resources forcommunication among some or all devices and equipment within its servicearea or cell. Within the present disclosure, as discussed further below,the scheduling entity may be responsible for scheduling, assigning,reconfiguring, and releasing resources for one or more scheduledentities. That is, for scheduled communication, UEs 106, which may bescheduled entities, may utilize resources allocated by the schedulingentity 108.

Base stations 108 are not the only entities that may function asscheduling entities. That is, in some examples, a UE may function as ascheduling entity, scheduling resources for one or more scheduledentities (e.g., one or more other UEs).

As illustrated in FIG. 1, a scheduling entity 108 may broadcast downlinktraffic 112 to one or more scheduled entities 106. Broadly, thescheduling entity 108 is a node or device responsible for schedulingtraffic in a wireless communication network, including the downlinktraffic 112 and, in some examples, uplink traffic 116 and/or uplinkcontrol information 118 from one or more scheduled entities 106 to thescheduling entity 108. On the other hand, the scheduled entity 106 is anode or device that receives downlink control information 114, includingbut not limited to scheduling information (e.g., a grant),synchronization or timing information, or other control information fromanother entity in the wireless communication network such as thescheduling entity 108.

In addition, the uplink and/or downlink control information and/ortraffic information may be time-divided into frames, subframes, slots,and/or symbols. As used herein, a symbol may refer to a unit of timethat, in an orthogonal frequency division multiplexed (OFDM) waveform,carries one resource element (RE) per sub-carrier. A slot may carry 7 or14 OFDM symbols in some examples. A subframe may refer to a duration of1 millisecond (ms). Multiple subframes or slots may be grouped togetherto form a single frame or radio frame. Of course, these definitions arenot required, and any suitable scheme for organizing waveforms may beutilized, and various time divisions of the waveform may have anysuitable duration.

In general, base stations 108 may include a backhaul interface forcommunication with a backhaul portion 120 of the wireless communicationsystem. The backhaul 120 may provide a link between a base station 108and the core network 102. Further, in some examples, a backhaul networkmay provide interconnection between the respective base stations 108.Various types of backhaul interfaces may be employed, such as a directphysical connection, a virtual network, or the like using any suitabletransport network.

The core network 102 may be a part of the wireless communication system100, and may be independent of the radio access technology used in theRAN 104. In some examples, the core network 102 may be configuredaccording to 5G standards (e.g., 5GC). In other examples, the corenetwork 102 may be configured according to a 4G evolved packet core(EPC), or any other suitable standard or configuration.

Referring now to FIG. 2, by way of example and without limitation, aschematic illustration of a RAN 200 is provided. In some examples, theRAN 200 may be the same as the RAN 104 described above and illustratedin FIG. 1. The geographic area covered by the RAN 200 may be dividedinto cellular regions (cells) that can be uniquely identified by a userequipment (UE) based on an identification broadcasted from one accesspoint or base station. FIG. 2 illustrates macrocells 202, 204, and 206,and a small cell 208, each of which may include one or more sectors (notshown). A sector is a sub-area of a cell. All sectors within one cellare served by the same base station. A radio link within a sector can beidentified by a single logical identification belonging to that sector.In a cell that is divided into sectors, the multiple sectors within acell can be formed by groups of antennas with each antenna responsiblefor communication with UEs in a portion of the cell.

Various base station arrangements can be utilized. For example, in FIG.2, two base stations 210 and 212 are shown in cells 202 and 204; and athird base station 214 is shown controlling a remote radio head (RRH)216 in cell 206. That is, a base station can have an integrated antennaor can be connected to an antenna or RRH by feeder cables. In theillustrated example, the cells 202, 204, and 206 may be referred to asmacrocells, as the base stations 210, 212, and 214 support cells havinga large size. Further, a base station 218 is shown in the small cell 208(e.g., a microcell, picocell, femtocell, home base station, home Node B,home eNode B, etc.) which may overlap with one or more macrocells. Inthis example, the cell 208 may be referred to as a small cell, as thebase station 218 supports a cell having a relatively small size. Cellsizing can be done according to system design as well as componentconstraints.

It is to be understood that the radio access network 200 may include anynumber of wireless base stations and cells. Further, a relay node may bedeployed to extend the size or coverage area of a given cell. The basestations 210, 212, 214, 218 provide wireless access points to a corenetwork for any number of mobile apparatuses. In some examples, the basestations 210, 212, 214, and/or 218 may be the same as the basestation/scheduling entity 108 described above and illustrated in FIG. 1.

Within the RAN 200, the cells may include UEs that may be incommunication with one or more sectors of each cell. Further, each basestation 210, 212, 214, and 218 may be configured to provide an accesspoint to a core network (e.g., as illustrated in FIG. 1) for all the UEsin the respective cells. For example, UEs 222 and 224 may be incommunication with base station 210; UEs 226 and 228 may be incommunication with base station 212; UEs 230 and 232 may be incommunication with base station 214 by way of RRH 216; and UE 234 may bein communication with base station 218. In some examples, the UEs 222,224, 226, 228, 230, 232, 234, 236, 238, 240, and/or 242 may be the sameas the UE/scheduled entity 106 described above and illustrated in FIG.1.

In some examples, an unmanned aerial vehicle (UAV) 220, which may be adrone or quadcopter, can be a mobile network node and may be configuredto function as a UE. For example, the UAV 220 may operate within cell202 by communicating with base station 210. In some examples, a UAV 220may be configured to function as a BS (e.g., serving a UE 236). That is,in some examples, a cell may not necessarily be stationary, and thegeographic area of the cell may move according to the location of amobile base station such as a UAV 220.

In the radio access network 200, the ability for a UE to communicatewhile moving, independent of its location, is referred to as mobility.The various physical channels between the UE and the radio accessnetwork are generally set up, maintained, and released under the controlof an access and mobility management function (AMF). The AMF (not shownin FIG. 2) may include a security context management function (SCMF)that manages the security context for both the control plane and theuser plane functionality, and a security anchor function (SEAF) thatperforms authentication.

A radio access network 200 may utilize DL-based mobility or UL-basedmobility to enable mobility and handovers (i.e., the transfer of a UE'sconnection from one radio channel to another). In a network configuredfor DL-based mobility, during a call with a scheduling entity, or at anyother time, a UE may monitor various parameters of the signal from itsserving cell as well as various parameters of neighboring cells.Depending on the quality of these parameters, the UE may maintaincommunication with one or more of the neighboring cells. During thistime, if the UE moves from one cell to another, or if signal qualityfrom a neighboring cell exceeds that from the serving cell for a givenamount of time, the UE may undertake a handoff or handover from theserving cell to the neighboring (target) cell. For example, UE 224(illustrated as a vehicle, although any suitable form of UE may be used)may move from the geographic area corresponding to its serving cell 202to the geographic area corresponding to a neighbor cell 206. When thesignal strength or quality from the neighbor cell 206 exceeds that ofthe serving cell 202 for a given amount of time, the UE 224 may transmita reporting message to its serving base station 210 indicating thiscondition. In response, the UE 224 may receive a handover command, andthe UE may undergo a handover to the cell 206.

In a network configured for UL-based mobility, UL reference signals fromeach UE may be utilized by the network to select a serving cell for eachUE. In some examples, the base stations 210, 212, and 214/216 maybroadcast unified synchronization signals (e.g., unified PrimarySynchronization Signals (PSSs), unified Secondary SynchronizationSignals (SSSs) and unified Physical Broadcast Channels (PBCH)). The UEs222, 224, 226, 228, 230, and 232 may receive the unified synchronizationsignals, derive the carrier frequency and slot timing from thesynchronization signals, and in response to deriving timing, transmit anuplink pilot or reference signal. The uplink pilot signal transmitted bya UE (e.g., UE 224) may be concurrently received by two or more cells(e.g., base stations 210 and 214/216) within the radio access network200. Each of the cells may measure a strength of the pilot signal, andthe radio access network (e.g., one or more of the base stations 210 and214/216 and/or a central node within the core network) may determine aserving cell for the UE 224. As the UE 224 moves through the radioaccess network 200, the network may continue to monitor the uplink pilotsignal transmitted by the UE 224. When the signal strength or quality ofthe pilot signal measured by a neighboring cell exceeds that of thesignal strength or quality measured by the serving cell, the network 200may handover the UE 224 from the serving cell to the neighboring cell,with or without informing the UE 224.

Although the synchronization signal transmitted by the base stations210, 212, and 214/216 may be unified, the synchronization signal may notidentify a particular cell, but rather may identify a zone of multiplecells operating on the same frequency and/or with the same timing. Theuse of zones in 5G networks or other next generation communicationnetworks enables the uplink-based mobility framework and improves theefficiency of both the UE and the network, since the number of mobilitymessages that need to be exchanged between the UE and the network may bereduced.

In various implementations, the air interface in the radio accessnetwork 200 may utilize licensed spectrum, unlicensed spectrum, orshared spectrum. Licensed spectrum provides for exclusive use of aportion of the spectrum, generally by virtue of a mobile networkoperator purchasing a license from a government regulatory body.Unlicensed spectrum provides for shared use of a portion of the spectrumwithout the need for a government-granted license. While compliance withsome technical rules is generally still required to access unlicensedspectrum, generally, any operator or device may gain access. Sharedspectrum may fall between licensed and unlicensed spectrum, whereintechnical rules or limitations may be required to access the spectrum,but the spectrum may still be shared by multiple operators and/ormultiple RATs. For example, the holder of a license for a portion oflicensed spectrum may provide licensed shared access (LSA) to share thatspectrum with other parties, e.g., with suitable licensee-determinedconditions to gain access.

The electromagnetic spectrum is often subdivided, based onfrequency/wavelength, into various classes, bands, channels, etc. In 5GNR two initial operating bands have been identified as frequency rangedesignations FR1 (410 MHz-7.125 GHz) and FR2 (24.25 GHz-52.6 GHz). Thefrequencies between FR1 and FR2 are often referred to as mid-bandfrequencies. Although a portion of FR1 is greater than 6 GHz, FR1 isoften referred to (interchangeably) as a “Sub-6 GHz” band in variousdocuments and articles. A similar nomenclature issue sometimes occurswith regard to FR2, which is often referred to (interchangeably) as a“millimeter wave” band in documents and articles, despite beingdifferent from the extremely high frequency (EHF) band (30 GHz-300 GHz)which is identified by the International Telecommunications Union (ITU)as a “millimeter wave” band.

With the above aspects in mind, unless specifically stated otherwise, itshould be understood that the term “sub-6 GHz” or the like if usedherein may broadly represent frequencies that may be less than 6 GHz,may be within FR1, or may include mid-band frequencies. Further, unlessspecifically stated otherwise, it should be understood that the term“millimeter wave” or the like if used herein may broadly representfrequencies that may include mid-band frequencies, may be within FR2, ormay be within the EHF band.

The air interface in the radio access network 200 may utilize one ormore multiplexing and multiple access algorithms to enable simultaneouscommunication of the various devices. For example, 5G NR specificationsprovide multiple access for UL transmissions from UEs 222 and 224 tobase station 210, and for multiplexing for DL transmissions from basestation 210 to one or more UEs 222 and 224, utilizing orthogonalfrequency division multiplexing (OFDM) with a cyclic prefix (CP). Inaddition, for UL transmissions, 5G NR specifications provide support fordiscrete Fourier transform-spread-OFDM (DFT-s-OFDM) with a CP (alsoreferred to as single-carrier FDMA (SC-FDMA)). However, within the scopeof the present disclosure, multiplexing and multiple access are notlimited to the above schemes, and may be provided utilizing timedivision multiple access (TDMA), code division multiple access (CDMA),frequency division multiple access (FDMA), sparse code multiple access(SCMA), resource spread multiple access (RSMA), or other suitablemultiple access schemes. Further, multiplexing DL transmissions from thebase station 210 to UEs 222 and 224 may be provided utilizing timedivision multiplexing (TDM), code division multiplexing (CDM), frequencydivision multiplexing (FDM), orthogonal frequency division multiplexing(OFDM), sparse code multiplexing (SCM), or other suitable multiplexingschemes.

The air interface in the radio access network 200 may further utilizeone or more duplexing algorithms. Duplex refers to a point-to-pointcommunication link where both endpoints can communicate with one anotherin both directions. Full-duplex means both endpoints can simultaneouslycommunicate with one another. Half-duplex means only one endpoint cansend information to the other at a time. Half-duplex emulation isfrequently implemented for wireless links utilizing time division duplex(TDD). In TDD, transmissions in different directions on a given channelare separated from one another using time division multiplexing. Thatis, at some times the channel is dedicated for transmissions in onedirection, while at other times the channel is dedicated fortransmissions in the other direction, where the direction may changevery rapidly, e.g., several times per slot. In a wireless link, afull-duplex channel generally relies on physical isolation of atransmitter and receiver, and suitable interference cancelationtechnologies. Full-duplex emulation is frequently implemented forwireless links by utilizing frequency division duplex (FDD) or spatialdivision duplex (SDD). In FDD, transmissions in different directionsoperate at different carrier frequencies. In SDD, transmissions indifferent directions on a given channel are separate from one anotherusing spatial division multiplexing (SDM). In other examples,full-duplex communication may be implemented within unpaired spectrum(e.g., within a single carrier bandwidth), where transmissions indifferent directions occur within different sub-bands of the carrierbandwidth. This type of full-duplex communication may be referred to assub-band full-duplex (SBFD), also known as flexible duplex.

In a further aspect of the RAN 200, sidelink signals may be used betweenUEs without necessarily relying on scheduling or control informationfrom a base station. For example, two or more UEs (e.g., UEs 226 and228) may communicate with each other using peer to peer (P2P) orsidelink signals 227 without relaying that communication through a basestation (e.g., base station 212). In a further example, UE 238 isillustrated communicating with UEs 240 and 242. Here, the UE 238 mayfunction as a scheduling entity or a primary sidelink device, and UEs240 and 242 may function as a scheduled entity or a non-primary (e.g.,secondary) sidelink device. In still another example, a UE may functionas a scheduling entity in a device-to-device (D2D), peer-to-peer (P2P),or vehicle-to-vehicle (V2V) network, and/or in a mesh network. In a meshnetwork example, UEs 240 and 242 may optionally communicate directlywith one another in addition to communicating with the UE 238 (e.g.,functioning as a scheduling entity). Thus, in a wireless communicationsystem with scheduled access to time-frequency resources and having acellular configuration, a P2P configuration, or a mesh configuration, ascheduling entity and one or more scheduled entities may communicateutilizing the scheduled resources. In some examples, the sidelinksignals 227 include sidelink traffic (e.g., a physical sidelink sharedchannel) and sidelink control (e.g., a physical sidelink controlchannel).

In some examples, two or more UEs (e.g., UEs 226 and 228) within thecoverage area of a serving base station 212 may communicate with boththe base station 212 using cellular signals and with each other usingdirect link signals (e.g., sidelink signals 227) without relaying thatcommunication through the base station. In an example of a V2X networkwithin the coverage area of the base station 212, the base station 212and/or one or both of the UEs 226 and 228 may function as schedulingentities to schedule sidelink communication between UEs 226 and 228.

Various aspects of the present disclosure will be described withreference to an OFDM waveform, an example of which is schematicallyillustrated in FIG. 3. It should be understood by those of ordinaryskill in the art that the various aspects of the present disclosure maybe applied to an SC-FDMA waveform in substantially the same way asdescribed herein below. That is, while some examples of the presentdisclosure may focus on an OFDM link for clarity, it should beunderstood that the same principles may be applied as well to SC-FDMAwaveforms.

Referring now to FIG. 3, an expanded view of an example DL subframe (SF)302A is illustrated, showing an OFDM resource grid 304. However, asthose skilled in the art will readily appreciate, the physical layer(PHY) transmission structure for any particular application may varyfrom the example described here, depending on any number of factors.Here, time is in the horizontal direction with units of OFDM symbols;and frequency is in the vertical direction with units of subcarriers. 5GNR supports a scalable numerology where different numerologies may beused for different radio frequency spectrums, different bandwidths, andthe like. For example, sub-carrier spacings (SCSs) of 15 kHz, 30 kHz, 60kHz, etc., may be used in different scenarios.

The resource grid 304 may be used to schematically representtime-frequency resources for a given antenna port. That is, in amultiple-input-multiple-output (MIMO) implementation with multipleantenna ports available, a corresponding multiple number of resourcegrids 304 may be available for communication. The resource grid 304 isdivided into multiple resource elements (REs) 306. An RE, which is 1subcarrier×1 symbol, is the smallest discrete part of the time-frequencygrid, and contains a single complex value representing data from aphysical channel or signal. Depending on the modulation utilized in aparticular implementation, each RE may represent one or more bits ofinformation. In some examples, a block of REs may be referred to as aphysical resource block (PRB) or more simply a resource block (RB) 308,which contains any suitable number of consecutive subcarriers in thefrequency domain. In one example, an RB may include 12 subcarriers, anumber independent of the numerology used. In some examples, dependingon the numerology, an RB may include any suitable number of consecutiveOFDM symbols in the time domain. Within the present disclosure, it isassumed that a single RB such as the RB 308 entirely corresponds to asingle direction of communication (either transmission or reception fora given device).

Scheduling of UEs (e.g., scheduled entities) for downlink, uplink, orsidelink transmissions typically involves scheduling one or moreresource elements 306 within one or more sub-bands or bandwidth parts(BWPs). Each BWP may include two or more contiguous or consecutive RBs.Thus, a UE generally utilizes only a subset of the resource grid 304. Insome examples, an RB may be the smallest unit of resources that can beallocated to a UE. Thus, the more RBs scheduled for a UE, and the higherthe modulation scheme chosen for the air interface, the higher the datarate for the UE. The RBs may be scheduled by a base station (e.g., gNB,eNB, RSU, etc.) or may be self-scheduled by a UE implementing D2Dsidelink communication.

In this illustration, the RB 308 is shown as occupying less than theentire bandwidth of the subframe 302A, with some subcarriers illustratedabove and below the RB 308. In a given implementation, the subframe 302Amay have a bandwidth corresponding to any number of one or more RBs 308.Further, in this illustration, the RB 308 is shown as occupying lessthan the entire duration of the subframe 302A, although this is merelyone possible example.

Each 1 ms subframe 302A may consist of one or multiple adjacent slots.In the example shown in FIG. 3, one subframe 302B includes four slots310, as an illustrative example. In some examples, a slot may be definedaccording to a specified number of OFDM symbols with a given cyclicprefix (CP) length. For example, a slot may include 7 or 14 OFDM symbolswith a nominal CP. Additional examples may include mini-slots having ashorter duration (e.g., one or two OFDM symbols). These mini-slots mayin some cases be transmitted occupying resources scheduled for ongoingslot transmissions for the same or for different UEs. Any number ofresource blocks may be utilized within a subframe or slot.

An expanded view of one of the slots 310 illustrates the slot 310including a control region 312 and a data region 314. In general, thecontrol region 312 may carry control channels (e.g., PDCCH), and thedata region 314 may carry data channels (e.g., PDSCH or PUSCH). Ofcourse, a slot may contain all DL, all UL, or at least one DL portionand at least one UL portion. The structure illustrated in FIG. 3 ismerely an example, and different slot structures may be utilized, andmay include one or more of each of the control region(s) and dataregion(s).

Although not illustrated in FIG. 3, the various REs 306 within a RB 308may be scheduled to carry one or more physical channels, includingcontrol channels, shared channels, data channels, etc. Other REs 306within the RB 308 may also carry pilots or reference signals, includingbut not limited to a demodulation reference signal (DMRS), a controlreference signal (CRS), or a sounding reference signal (SRS). Thesepilots or reference signals may provide for a receiving device toperform channel estimation of the corresponding channel, which mayenable coherent demodulation/detection of the control and/or datachannels within the RB 308.

In some examples, a slot 310 may be utilized for broadcast or unicastcommunication. In V2X or D2D networks, a broadcast communication mayrefer to a point-to-multipoint transmission by a one device (e.g., avehicle, base station (e.g., RSU, gNB, eNB, etc.), UE, or other similardevice) to other devices. A unicast communication may refer to apoint-to-point transmission by a one device to a single other device.

In an example, the control region 312 of the slot 310 may include aphysical downlink control channel (PDCCH) including downlink controlinformation (DCI) transmitted by a base station (e.g., gNB, eNB, RSU,etc.) towards one or more of a set of UEs, which may include one or moresidelink devices (e.g., V2X/D2D devices). In some examples, the DCI mayinclude synchronization information to synchronize communication by aplurality of sidelink devices on the sidelink channel. In addition, theDCI may include scheduling information indicating one or more resourceblocks within the control region 312 and/or data region 314 allocated tosidelink devices for sidelink communication. For example, the controlregion 312 of the slot may further include control informationtransmitted by sidelink devices over the sidelink channel, while thedata region 314 of the slot 310 may include data transmitted by sidelinkdevices over the sidelink channel. In some examples, the controlinformation may be transmitted within a physical sidelink controlchannel (PSCCH), while the data may be transmitted within a physicalsidelink shared channel (PSSCH).

In a DL transmission (e.g., over the Uu interface), the transmittingdevice (e.g., the scheduling entity) may allocate one or more REs 306(e.g., within a control region 312) to carry DL control informationincluding one or more DL control channels, such as a PBCH; and/or aphysical downlink control channel (PDCCH), etc., to one or morescheduled entities. The transmitting device may further allocate one ormore REs 306 to carry other DL signals, such as a DMRS; a phase-trackingreference signal (PT-RS); a channel state information-reference signal(CSI-RS); a primary synchronization signal (PSS); and a secondarysynchronization signal (SSS).

The synchronization signals PSS and SSS, and in some examples, the PBCHand a PBCH DMRS, may be transmitted in a synchronization signal block(SSB) that includes 3 consecutive OFDM symbols, numbered via a timeindex in increasing order from 0 to 3. In the frequency domain, the SSBmay extend over 240 contiguous subcarriers, with the subcarriers beingnumbered via a frequency index in increasing order from 0 to 239. Ofcourse, the present disclosure is not limited to this specific SSBconfiguration. Other nonlimiting examples may utilize greater or fewerthan two synchronization signals; may include one or more supplementalchannels in addition to the PBCH; may omit a PBCH; and/or may utilize adifferent number of symbols and/or nonconsecutive symbols for an SSB,within the scope of the present disclosure.

The SSB may be used to send system information (SI) and/or provide areference to SI transmitted via another channel. Examples of systeminformation may include, but are not limited to, subcarrier spacing,system frame number, a cell global identifier (CGI), a cell barindication, a list of common control resource sets (coresets), a list ofcommon search spaces, a search space for system information block 1(SIB1), a paging search space, a random access search space, and uplinkconfiguration information. Two specific examples of coresets includePDCCH CORESET 0 and CORESET 1.

The PDCCH may carry downlink control information (DCI) including but notlimited to power control commands, scheduling information, a grant,and/or an assignment of REs for DL and UL transmissions. The PHY carriesHARQ feedback transmissions such as an acknowledgment (ACK) or negativeacknowledgment (NACK). HARQ is a technique well-known to those ofordinary skill in the art, wherein the integrity of packet transmissionsmay be checked at the receiving side for accuracy, e.g., utilizing anysuitable integrity checking mechanism, such as a checksum or a cyclicredundancy check (CRC). If the integrity of the transmission isconfirmed, an ACK may be transmitted, whereas if not confirmed, a NACKmay be transmitted. In response to a NACK, the transmitting device maysend a HARQ retransmission, which may implement chase combining,incremental redundancy, etc.

In an UL transmission (e.g., over the Uu interface), the transmittingdevice (e.g., the scheduled entity) may utilize one or more REs 306 tocarry UL control information including one or more UL control channels,such as a physical uplink control channel (PUCCH), to the schedulingentity. UL control information may include a variety of packet types andcategories, including pilots, reference signals, and informationconfigured to enable or assist in decoding uplink data transmissions.For example, the UL control information may include a DMRS or SRS. Insome examples, the control information may include a scheduling request(SR), i.e., a request for the scheduling entity to schedule uplinktransmissions. Here, in response to the SR transmitted on the controlchannel, the scheduling entity may transmit downlink control informationthat may schedule resources for uplink packet transmissions. UL controlinformation may also include HARQ feedback, channel state feedback(CSF), or any other suitable UL control information.

In addition to control information, one or more REs 306 (e.g., withinthe data region 314) may be allocated for user data or traffic data.Such traffic may be carried on one or more traffic channels, such as,for a DL transmission, a PDSCH; or for an UL transmission, a physicaluplink shared channel (PUSCH). In some examples, one or more REs 306within the data region 314 may be configured to carry SIBs (e.g., SIB1),carrying system information that may enable access to a given cell.

The physical channels described above are generally multiplexed andmapped to transport channels for handling at the medium access control(MAC) layer. Transport channels carry blocks of information calledtransport blocks (TB). The transport block size (TBS), which maycorrespond to a number of bits of information, may be a controlledparameter, based on the modulation and coding scheme (MCS) and thenumber of RBs in a given transmission.

The channels or carriers described above with reference to FIGS. 1-3 arenot necessarily all of the channels or carriers that may be utilizedbetween a scheduling entity and scheduled entities, and those ofordinary skill in the art will recognize that other channels or carriersmay be utilized in addition to those illustrated, such as other traffic,control, and feedback channels.

Example Handover Operations

The disclosure relates in some aspects to handover of a UE between afirst mode of operation and a second mode of operation. In someexamples, the first mode of operation involves master cell group (MCG)connectivity and the second mode of operation involves multiple radioaccess technology-dual connectivity (MR-DC).

In some examples, the first mode of operation is a standalone mode ofoperation and the second mode of operation is a non-standalone mode ofoperation. In a standalone mode of operation, a device (e.g., a UE) usesa single radio access technology (RAT). Three standalone options aredefined by the 3rd Generation Partnership Project (3GPP). Option 1involves 4G evolved packet core (EPC) and 3GPP Long-Term Evolution (LTE)eNB access (e.g., as in a 4G LTE network). Option 2 involves 5G corenetwork (5GC) and New Radio (NR) gNB access. Option 3 involves 5GC andLTE Next Generation-eNB (ng-eNB) access.

In a non-standalone mode of operation, a device (e.g., a UE) usesmultiple radio access technologies (RATs). Three non-standalone optionsare defined by 3GPP. Option 3 involves using EPC and an LTE eNB actingas a master base station and an NR en-gNB acting as a secondary basestation. Option 4 involves 5GC and NR gNB access. Option 5 involves 5GCand ng-eNB access.

In some examples, inter-system (e.g., inter-RAT) handover refers tohandover between different types of core networks (e.g., between a 4Gevolved packet core (EPC) core network and a 5G core network, 5GC). Forexample, SA to NSA handover may be used in Evolved Packet System (EPS)fallback scenarios, such as Option 2 (NR connected to 5G core network,5GC) to Option 3 (E-UTRAN NR-dual connectivity, EN-DC) handover. As aspecific example, when a UE with an ongoing high-performance demand dataservice needs to perform a mobile oriented (MO) or mobile terminated(MT) voice call but Voice over NR (VoNR) is not supported, falling-backto EPS and keeping NR as the secondary node (SN) may help to preserve agood user experience (e.g., by maintaining ongoing data service).

FIG. 4 is a schematic illustration of a wireless communication system400 where a UE 402 may be handed-over from an SA mode to an NSA mode, orvice versa. The wireless communication system 400 includes a first corenetwork 404 (e.g., an LTE network) and a second core network 406 (e.g.,an NR network), and potentially other networks (not shown).

In the example, of FIG. 4, the UE 402 may operate in an SA mode 408whereby the UE 402 is initially connected to a source base station 410(e.g., a gNB) of the second core network 406. At some point in time, theUE 402 may be subject to an inter-system SA to NSA handover 412 (e.g.,to obtain a service via the other network).

In the example of FIG. 4, in an NSA mode 414, the UE 402 may connect toa master base station 416 (e.g., an eNB) in the first core network 404and a secondary base station (e.g., a gNB) 418. As discussed herein, insome scenarios, the source base station 410 may be designated as thesecondary base station for the NSA mode.

In some examples, the source base station 410, the master base station416, and the secondary base station 418 may correspond to any of the BSsor scheduling entities shown in any of FIGS. 1, 2, 5, 6, 7, 15, 20, and21. In some examples, the UE 402 may correspond to any of the UEs orscheduled entities shown in any of FIGS. 1, 2, 5, 6, 7, 12, 18, and 19.

SA to NSA inter-system handover may include for, example, Option 2(NR/5GC) to Option 3 (EN-DC) handover as well as Option 5 (LTE/5GC) toOption 3 (EN-DC) handover. Option 2 to Option 3 handover may beparticularly useful. For example, when a UE with an ongoinghigh-performance demand data service needs to perform a mobile oriented(MO) or mobile terminated (MT) voice call but Voice over NR (VoNR) isnot supported by the NR core network, the UE may fall-back to an EPScore network for the voice call while keeping the source NG-RAN node asthe secondary node (SN) to preserve a good user experience (e.g., bymaintaining the ongoing high-performance data service on the SN).

NSA to SA inter-system handover includes the reverse of the abovescenarios. Again, using voice fallback as an example, after the voicecall ends, the network may handover the UE from NSA Option 3 to SAOption 2 to save UE power. In the handover, it is possible that thetarget node does not support DC. Thus, the UE will go back to an SA modeof operation.

FIG. 5 illustrates an example of an NR SA to EN-DC handover procedure500 where the source gNB is selected as the target SN. In this example,a UE 502 is initially connected to a source base station in an SA modeof operation. The source base station is designated as a Source gNB 504in FIG. 5. The source base station could take other forms in otherimplementations. The UE 502 is subsequently handed-over to a target basestation. The target base station is designated as a Target eNB 506. Thetarget base station could take other forms in other implementations. Insome examples, the source base station and the target base station maycorrespond to any of the BSs or scheduling entities shown in any ofFIGS. 1, 2, 4, 6, 7, 15, 20, and 21. In some examples, the UE 502 maycorrespond to any of the UEs or scheduled entities shown in any of FIGS.1, 2, 4, 6, 7, 12, 18, and 19.

At step 1, the Source gNB 504 starts the handover procedure byinitiating the Handover Required procedure. In this case, to induce theTarget eNB 506 to select the Source gNB 504 as the target SN, the SourcegNB 504 may include both an NR measurement result (e.g.,candidateCellInfoListNR-r15) and candidate E-UTRA cell information in aradio resource control (RRC) container of an NG-AP Handover Requiredmessage and the source NG-RAN node ID.

At step 2, the AMF/5GC 508 sends a Relocation Request to the targetmobility management entity (MME) 510. The MME 510 starts to create asession on the serving gateway (SGW) 512. At step 3, the MME 510 sends aHandover Request to the Target eNB 506. Thus, the Target eNB 506 mayreceive the RRC container of an NG-AP Handover Required message fromstep 1. At step 4, the Target eNB 506 sends an SgNB Addition Request tothe Source gNB 504 which has been selected as the Target SN. Forexample, based on one or more of the QoS profile of the enhanced radioaccess bearers (E-RABs) (e.g., forwarded by step 2 and step 3), the DCcapability of the UE 502, the NR measurement result, local policy, or acombination thereof, the Target eNB 506 may decide to configure thetarget secondary gNB (SgNB) for the UE 502. The Source gNB 504 may bepreferred here based on the NR measurement result in step 1.

At step 5, the Target SN replies with an SgNB Addition Request Ack. Atstep 6, the Target eNB 506 replies to the MME 510 with a HandoverRequest Ack. At step 7, the MME 510 replies to the AMF/5GC 508 with aRelocation Request Ack. At step 8, the AMF/5GC 508 sends a HandoverCommand to the Source gNB 504. At step 9, the Source gNB 504 triggersthe UE 502 to perform the handover and apply the new configuration.

At step 10, the UE 502 synchronizes to the Target eNB 506 (e.g., byconducting a random access procedure). At step 11, the UE 502 replies tothe Target eNB 506 with an eNB RRC Connection Reconfiguration completemessage. Of note, the UE 502 does not need to synchronize to the TargetSN in this procedure since the Source gNB 504 is the target SN.

At step 12, if the RRC connection reconfiguration procedure wassuccessful, the Target eNB 506 informs the Target SN of this via an SgNBReconfiguration Complete message. The system may then perform dataforwarding operations 514, tracking area update operations 516, andother operations as needed.

FIG. 6 illustrates an example of an NR SA to EN-DC handover procedure600. An NR SA to EN-DC inter-system handover may need to be performed,for example, in a scenario where an IP multimedia subsystem (IMS) voicecall is initiated in an NR SA system with ongoing data flows in the casewhere Voice over NR (VoNR) is not supported. In this case, a handover toan EN-DC system can be performed so that the ongoing data flows arecontinued over the NR SCG leg while the voice call is carried over anLTE master cell group (MCG) leg.

In this example, a UE 602 is initially connected to a source basestation in an SA mode of operation where a protocol data unit (PDU)session and QoS flows are setup in a 5G system (5GS). The source basestation is designated as a Source NR-RAN 604 in FIG. 6. The source basestation could take other forms in other implementations. The UE 602 issubsequently handed-over to a target base station. The target basestation is designated as a Master eNB (MeNB) 606. The target basestation could take other forms in other implementations. In someexamples, the source base station and the target base station maycorrespond to any of the BSs or scheduling entities shown in any ofFIGS. 1, 2, 4, 5, 7, 15, 20, and 21. In some examples, the UE 602 maycorrespond to any of the UEs or scheduled entities shown in any of FIGS.1, 2, 4, 5, 7, 12, 18, and 19.

At step 1, the Source NR-RAN 604 starts the handover procedure byinitiating the Handover Required procedure. In this case, to induce theMaster eNB 606 to select the Source NR-RAN 604 as the target SN, theSource NR-RAN 604 may include one or more of a Target MeNB ID, aHandover Type (e.g., 5GStoEPS), and a Source to Target TransparentContainer. The Source to Target Transparent Container may include UEmeasurement results, an EPS fallback of IMS voice indication, and anindication that Target SgNB ID=Source NG-RAN node ID).

At step 2, the AMF 608 sends a Relocation Request to the target mobilitymanagement entity (MME) 610. The MME 610 starts to create a session onthe serving gateway (SGW) 612. At step 3, the MME 610 sends a HandoverRequest to the Master eNB 606. Thus, the Master eNB 606 may receive thecontainer from step 1. At step 4, the Master eNB 606 sends an SNAddition Request to the Source NR-RAN 604. In some examples, based onone or more of the QoS profile of the enhanced radio access bearers(E-RABs) (e.g., forwarded by step 2 and step 3), the DC capability ofthe UE 602, the NR measurement result, local policy, or a combinationthereof, the Master eNB 606 may decide to configure the target secondarygNB (SgNB) for the UE 602. The Source NR-RAN 604 may be preferred herebased on the NR measurement result in step 1.

At step 5, the Target SN replies with an SN Addition Request Ack. Atstep 6, the Master eNB 606 replies to the MME 610 with a HandoverRequest Ack. At step 7, the MME 610 replies to the AMF/5GC 608 with aRelocation Response. At step 8, the AMF 608 sends a Handover Command tothe Source NR-RAN 604. At step 9, the Source NR-RAN 604 triggers the UE602 to perform the handover and apply the new configuration.

The UE 602 then performs the handover procedure. Here, the IMS voicecall is set up over the MCG leg.

Example Signaling of Delta Configuration

In an NR SA to EN-DC handover, if during handover preparation the targetSgNB is selected to be the source NG-RAN node, then the SCGconfiguration provided to the UE for use after handover may involve fewchanges compared to the configuration used by the UE before handover.For instance, in the EPS fallback of IMS voice scenario mentioned above,the ongoing data flows related to the data radio bearers (DRBs) can becontinued after handover over the SCG leg. Thus, the DRB configurationscan be re-used. In this scenario, signaling of the delta configurationin the handover command message carrying the RRC reconfiguration mayprovide one or more advantages. For example, if a delta configuration isprovided, the complexity and time for processing the handover commandmessage at the UE is reduced, which may reduce of handover latency.

Thus, in some handover (e.g., NR SA to EN-DC handover) scenarios (e.g.,EPS fallback of IMS voice), if the target SgNB is selected to be thesource NG-RAN node, then the SCG configuration provided to the UE in thehandover command message may involve relatively few changes compared tothe UE configuration before handover. In such scenarios, signaling of adelta configuration for SCG in the handover command message may beadvantageous. Signaling of a delta configuration for SCG may have theadvantage of reducing the complexity and time for processing thehandover message at the UE because parts of the source configurations ofprotocol layers could be reused, which contributes to a reduction inhandover latency.

The disclosure relates in some aspects to using the existing fullConfigIE in the handover command message carrying the RRC reconfiguration toindicate to the UE whether a delta SCG configuration is being provided(e.g., whether the SCG configuration provided is a delta compared to theUE configuration before handover).

In the case of NR SA to EN-DC handover, the fullConfig IE may beinterpreted by the UE in the following way in some examples.

If the fullConfig IE is not present, the UE interprets the IE as followsin some examples. The SCG configuration provided is a delta compared tothe UE configuration before handover. In particular, the following UEconfigurations before handover are reused for the SCG: service dataapplication protocol (SDAP) and packet data convergence protocol (PDCP)configurations of DRBs, Physical layer and MAC layer configurations, andradio link control (RLC) configurations of DRBs. Alternatively or inaddition, the full MCG configuration may provided in the RRCreconfiguration message.

If the fullConfig IE is present, the UE interprets the IE in aconventional manner in some examples. Full MCG and SCG configurationsmay be provided in the RRC reconfiguration message.

In the case of NR SA to EN-DC handover, the fullConfig IE in the LTERRCConnectionReconfiguration message included in MobilityFromNRCommand(handover command message) may be used to indicate to the UE whether theprovided NR SCG configuration is a delta compared to the UEconfiguration before handover.

In the case of NR SA to EN-DC handover, the fullConfig IE may beinterpreted by the UE as follows in some examples. If the fullConfig IEis not present, the SCG configuration provided is a delta compared tothe UE configuration before handover. The MCG configuration provided isa full configuration. If the fullConfig IE is present, theinterpretation may follow the conventional practice, e.g., full MCG andSCG configurations are provided.

In the case of NR SA to EN-DC handover, if a delta SCG configuration isprovided, the following UE configurations before handover may be reusedfor the SCG: SDAP and PDCP configurations of DRBs, Physical layer andMAC layer configurations, and RLC configurations of DRBs.

The disclosure relates in some aspects to signaling of a deltaconfiguration for inter-system handover from a 5G new radio (NR)standalone (SA) mode of operation to an E-UTRAN NR-dual connectivity(EN-DC) mode of operation.

In SA to NSA inter-system handover, if the target SgNB is selected to bethe source NG-RAN node, the SCG configuration provided to the UE for useafter handover may involve relatively few changes compared toconfiguration used by the UE before handover. For example, if an IMSvoice call is initiated in NR SA and VoNR is not supported, then ahandover to EN-DC can be performed so that ongoing data flows arecontinued over the SCG leg whereas the voice call is carried over theMCG leg.

The disclosure relates in some aspects to using the fullConfiginformation element (IE) in the RRC reconfiguration message to indicateto the UE whether or not a full SCG configuration is being provided inthe handover command for SA to NSA inter-system handover. If a deltaconfiguration is provided, the complexity and time for processing themessage can be reduced at the UE. For example, if the UE is able toreuse at least some of the configuration information associated with asource cell, the UE does not need to receive and process thisconfiguration information (e.g., it is already maintained at the UE) inthis case. Moreover, if the UE is able to reuse at least some of theconfiguration information associated with a source cell, the UE does notneed to verify that it supports the configuration. In contrast, the UEmay need to verify that it supports a configuration that it receivesfrom the network.

In the case of SA to NSA inter-system handover, if the fullConfig IE ispresent, the UE may interpret this as indicating that full MCG and SCGconfigurations are provided in the reconfiguration message.

If the fullConfig IE is not present, the UE may interpret this asindicating that: 1) a full MCG configuration is provided in thereconfiguration message; and 2) the SCG configuration provided is adelta compared to the configuration used by the UE before handover.

In some examples, the following configurations of the UE before handovermay be reused for the SCG: UE SDAP configurations of data radio bearers(DRBs), UE PDCP configurations of DRBs; UE physical layer; UE MAC layer;and UE RLC configurations of DRBs. Other types of configurations may bereused in accordance with the teachings herein.

Some types of configurations might not be reused. For example, asecurity configuration may be obtained at the target.

An example of a message definition for fullConfig IE follows in Table 1.In this example, the feature “for handover (HO) from NR to EN-DC,fullConfig indicates whether or not delta signaling is applicable of:SDAP and PDCP configurations of SCG DRBs from the UE SDAP and PDCPconfigurations of DRBs before handover, and SCG physical layer, MAClayer, and RLC configurations of DRBs from the UE physical layer, MAClayer, and RLC configurations of DRBs before handover” is shown as beingincorporated into section 6.2.2 of 3GPPP 36.331 Rel. 15.8. ThefullConfig IE may be configured in a different manner in otherimplementations.

TABLE 1 RRCConnectionReconfiguration-IEs field descriptions fullConfigIndicates the full configuration option is applicable for the RRCConnection Reconfiguration message for intra-system intra-RAT handover.For inter-RAT handover from NR to E-UTRA, fullConfig indicates whetheror not delta signalling of SDAP/PDCP from source RAT is applicable. ForHO from NR to EN-DC, fullConfig indicates whether or not deltasignalling is applicable of:  SDAP and PDCP configurations of SCG DRBsfrom the UE SDAP  and PDCP configurations of DRBs before handover, and SCG physical layer, MAC layer, and RLC configurations of DRBs  from theUE physical layer, MAC layer, and RLC configurations of  DRBs beforehandover.

The disclosure relates in some aspects to signaling for handover toE-UTRA. In some examples, the purpose of this procedure is to, under thecontrol of the network, transfer a connection between the UE and anotherRadio Access Network (e.g., GERAN, UTRAN or NR) to E-UTRAN including thecase of NR to EN-DC handover, or transfer a connection between the UEand the E-UTRAN with one type of core network (CN) to the E-UTRAN with adifferent type of CN.

The handover to E-UTRA procedure applies when signaling radio bearers(SRBs), possibly in combination with DRBs, are established in anotherRAT or in E-UTRA connected to another type of CN. Handover from UTRAN toE-UTRAN applies after integrity has been activated in UTRAN. Handover toE-UTRA connected to a different type of CN applies after integrity hasbeen activated in E-UTRAN. Handover from NR to E-UTRAN applies afterintegrity has been activated in NR.

An example of reception of the RRCConnectionReconfiguration message by aUE is described in Table 2. In this example, the feature “if theRRCConnectionReconfiguration message does not include the fullConfig andthe UE is performing a handover from NR to EN-DC: configure the SCGphysical layer, MAC layer, and RLC configurations of DRBs by re-usingthe source physical layer, MAC layer, and RLC configurations of DRBs;and configure the SDAP and PDCP configurations of SCG DRBs by re-usingthe source SDAP and PDCP configurations of DRBs” is shown as beingincorporated into section 5.4.2.3 of 3GPPP 36.331 Rel. 15.8. Theseoperations may take other forms in other examples.

TABLE 2 Reception of the RRCConnectionReconfiguration by the UE If theUE is able to comply with the configuration included in theRRCConnectionReconfiguration message, the UE shall: 1> if theRRCConnectionReconfiguration message does not include the fullConfig andthe UE is connected to 5GC (i.e., delta signalling during intra 5GChandover):  2> re-use the source SDAP and PDCP configurations (i.e.,current SDAP/PDCP configurations for all RBs from source RAT prior tothe reception of the inter-RAT handover RRCConnectionReconfigurationmessage); 1> if the RRCConnectionReconfiguration message does notinclude the fullConfig and the UE is performing a handover from NR toEN-DC:  2> configure the SCG physical layer, MAC layer, and RLCconfigurations of DRBs by re- using the source physical layer, MAClayer, and RLC configurations of DRBs;  2> configure the SDAP and PDCPconfigurations of SCG DRBs by re-using the source SDAP and PDCPconfigurations of DRBs; 1> apply the default physical channelconfiguration as specified in 9.2.4; 1> apply the defaultsemi-persistent scheduling configuration as specified in 9.2.3; 1> applythe default MAC main configuration as specified in 9.2.2; 1> start timerT304 with the timer value set to t304, as included in themobilityControlInfo; 1> consider the target PCell to be one on thefrequency indicated by the carrierF req with a physical cell identityindicated by the targetPhysCellId; 1> start synchronising to the DL ofthe target PCell; 1> set the C-RNTI to the value of the newUE-Identity;1> for the target PCell, apply the downlink bandwidth indicated by thedl-Bandwidth; 1> for the target PCell, apply the uplink bandwidthindicated by (the absence or presence of) the ul-Bandwidth; 1> configurelower layers in accordance with the received radioResourceConfigCommon;1> configure lower layers in accordance with any additional fields, notcovered in the previous, if included in the receivedmobilityControlInfo; 1> perform the radio resource configurationprocedure as specified in 5.3.10; 1> if the handoverType insecurityConfigHO is set to fivegc-ToEPC:  2> indicate to higher layerthat the CN has changed from 5GC to EPC;  2> derive the key K_(eN) basedon the mapped K_(ASME) key as specified for interworking between EPS and5GS in TS 33.501 [86];  2> store the nextHopChainingCount-r15 value;1> else if the handoverType in securityConfigHO is set to intra5GC: 2> if the keyChangeIndicator-r15 received in the securityConfigHO isset to TRUE:   3> forward nas-Container to the upper layers, ifincluded;   3> update the K_(eNB) key based on the K_(AMF) key, asspecified in TS 33.501 [86];  2> else:   3> update the K_(eNB) key basedon the current K_(gNB) or the NH, using the nextHopChainingCount-r15value indicated in the SecurityConfigHO, as specified in TS 33.501 [86]; 2> store the nextHopChainingCount-r15 value; 1> else if thehandoverType in securityConfigHO is set to epc-To5GC:  2> forward thenas-Container to the upper layers  2> derive the K_(eNB) key, asspecified in TS 33.501 [86]; 1> else:  2> forward thenas-SecurityParamToEUTRA to the upper layers;  2> derive the K_(eNB)key, as specified in TS 33.401 [32]; 1> derive the K_(RRCint) keyassociated with the integrityProtAlgorithm, as specified in TS 33.401[32];  1> derive the K_(RRCenc) key and the K_(UPenc) key associatedwith the cipheringAlgorithm, as specified in TS 33.401 [32]; 1> if thereceived RRCConnectionReconfiguration includes the nr-SecondaryCellGroupConfig:  2> perform NR RRC Reconfiguration asspecified in TS 38.331 [82], clause 5.3.5.3. 1> if the receivedRRCConnectionReconfiguration includes the sk-Counter:  2> perform keyupdate procedure as specified in in TS 38.331 [82], clause 5.3.5.7;1> if the received RRCConnectionReconfiguration includes thenr-RadioBearerConfig1:  2> perform radio bearer configuration asspecified in TS 38.331 [82], clause 5.3.5.6; 1> if the receivedRRCConnectionReconfiguration includes the nr-RadioBearerConfig2: 2> perform radio bearer configuration as specified in TS 38.331 [82],clause 5.3.5.6. 1> if the handoverType in securityConfigHO is set tofivegc-ToEPC or if the handoverType-v1530 is not present:  2> configurelower layers to apply the indicated integrity protection algorithm andthe K_(RRCint) key immediately, i.e. the indicated integrity protectionconfiguration shall be applied to all subsequent messages received andsent by the UE, including the message used to indicate the successfulcompletion of the procedure;  2> configure lower layers to apply theindicated ciphering algorithm, the K_(RRCenc) key and the K_(UPenc) keyimmediately, i.e. the indicated ciphering configuration shall be appliedto all subsequent messages received and sent by the UE, including themessage used to indicate the successful completion of the procedure;1> if the received RRCConnectionReconfiguration includes thesCellToAddModList:  2> perform SCell addition as specified in 5.3.10.3b;1> if the RRCConnectionReconfiguration message includes the measConfig: 2> perform the measurement configuration procedure as specified in5.5.2; 1> perform the measurement identity autonomous removal asspecified in 5.5.2.2a; 1> if the RRCConnectionReconfiguration messageincludes the otherConfig:  2> perform the other configuration procedureas specified in 5.3.10.9; 1> if the RRCConnectionReconfiguration messageincludes wlan-OffloadInfo: 2> perform the dedicated WLAN offloadconfiguration procedure as specified in 5.6.12.2; 1> if theRRCConnectionReconfiguration message includes rclwi-Configuration: 2> perform the WLAN traffic steering command procedure as specified in5.6.16.2; 1> if the RRCConnectionReconfiguration message includeslwa-Configuration:  2> perform the LWA configuration procedure asspecified in 5.6.14.2; 1> if the RRCConnectionReconfiguration messageincludes lwip-Configuration:  2> perform the LWIP reconfigurationprocedure as specified in 5.6.17.2; 1> set the content ofRRCConnectionReconfigurationComplete message as follows:  2> if the UEhas radio link failure or handover failure information available inVarRLF- Report and if the RPLMN is included in plmn-IdentityList storedin VarRLF-Report:   3> include rlf-InfoAvailable;  2> if the UE hasMBSFN logged measurements available for E-UTRA and if the RPLMN isincluded in plmn-IdentityList stored in VarLogMeasReport and if T330 isnot running:   3> include logMeasAvailableMBSFN;  2> else if the UE haslogged measurements available for E-UTRA and if the RPLMN is included inplmn-IdentityList stored in VarLogMeasReport:   3> include thelogMeasAvailable;  2> if the UE has Bluetooth logged measurementsavailable and if the RPLMN is included in plmn-IdentityList stored inVarLogMeasReport:   3> include the logMeasAvailableBT;  2> if the UE hasWLAN logged measurements available and if the RPLMN is included inplmn-IdentityList stored in VarLogMeasReport:   3> include thelogMeasAvailableWLAN;  2> if the UE has connection establishment failureinformation available in VarConnEstFailReport and if the RPLMN is equalto plmn-Identity stored in VarConnEstFailReport:   3> includeconnEstFailInfoAvailable; 1> submit theRRCConnectionReconfigurationComplete message to lower layers fortransmission using the new configuration; 1> if theRRCConnectionReconfiguration message does not include rlf-TimersAndConstants set to setup:  2> use the default values specified in9.2.5 for timer T310, T311 and constant N310, N311; 1> if MACsuccessfully completes the random access procedure:  2> stop timer T304;2> apply the parts of the CQI reporting configuration, the schedulingrequest configuration and the sounding RS configuration that do notrequire the UE to know the SFN of the target PCell, if any;  2> applythe parts of the measurement and the radio resource configuration thatrequire the UE to know the SFN of the target PCell (e.g. measurementgaps, periodic CQI reporting, scheduling request configuration, soundingRS configuration), if any, upon acquiring the SFN of the target PCell;NOTE 1: Whenever the UE shall setup or reconfigure a configuration inaccordance with a field that is received it applies the newconfiguration, except for the cases addressed by the above statements.2> enter E-UTRA RRC_CONNECTED, upon which the procedure ends; NOTE 2:The UE is not required to determine the SFN of the target PCell byacquiring system information from that cell before performing RACHaccess in the target PCell. NOTE 3: If the handover is from NR andtarget CN is 5GC, the delta configuration on PDCP and SDAP can be usedfor intra-system inter-RAT handover.

The disclosure relates in some aspects to signaling a deltaconfiguration for other types of inter-system handover that involvemulti-connectivity. Examples of multi-connectivity include dualconnectivity (DC) and multi-RAT connectivity (e.g., multi-RAT dualconnectivity, MR-DC).

A first example relates to standalone NR to NR-DC handover. Thisinvolves the secondary node (SN) addition of an NG-RAN node where themaster cell group (MCG) before handover becomes the secondary cell group(SCG) after handover.

A second example relates to standalone LTE to LTE dual connectivityhandover. Here, the MCG before handover becomes the SCG after handover.

A third example relates to EN-DC to NR. For example, in EN-DC with dataflows carried over SCG and IMS voice carried over MCG, once the voicecall is over, the network may direct the UE to switch to NR SA. In thiscase, the UE may be provided a configuration in the handover commandthat is a delta of the SCG configuration before handover.

A fourth example relates to EN-DC to NR-DC. In some examples, this couldbe a slight variant of Case 3, where an NR node is added during theswitch to NR SA to handle additional data traffic where SCG beforehandover becomes MCG after handover and also adds a new SCG duringhandover.

In general, a per node (per cell group) delta configuration indicationcan be provided in the RRC reconfiguration message. For this generalsolution, two new IEs may be used.

A fullConfigMCG IE may be included in, for example, the MCGconfiguration portion of the RRC reconfiguration message. This IE mayindicate whether a full MCG configuration is provided.

A fullConfigSCG IE may be included in the SCG configuration portion ofthe RRC reconfiguration message. This IE may indicate whether a full SCGconfiguration is provided.

The manner in which a UE interprets the indications in a given scenario(e.g., a particular type of handover) and applies the configurationprovided may take different forms in different implementations.

FIG. 7 is a schematic illustration of a wireless communication system700 (e.g., the RAN 200 of FIG. 2) that performs handover as taughtherein. The wireless communication system 700 includes a first wirelesscommunication device 702 (e.g., a base station) and a second wirelesscommunication device 704 (e.g., a UE), and potentially other devices(not shown). In some examples, the first device 702 may correspond toany of the BSs or scheduling entities shown in any of FIGS. 1, 2, 4, 5,6, 15, 20, and 21. In some examples, the second device 704 maycorrespond to any of the UEs or scheduled entities shown in any of FIGS.1, 2, 4, 5, 6, 7, 12, 18, and 19.

The first device 702 includes a communication controller 706 forcontrolling communications with (e.g., transmitting to and/or receivingfrom) the second device 704 and/or other devices via a transceiver 708.The second device 704 includes a communication controller 710 forcontrolling communications with (e.g. transmitting to and/or receivingfrom) the first device 702 and/or other devices via a transceiver 712.

The communication controller 706 includes a handover controller 714 forcontrolling handover at the network side as taught herein. For example,in response to a received handover command, the handover controller 714may send an RRC ConnectionReconfiguration message 716 to the device 704via the transceiver 708. In scenarios where the handover controller 714includes all pertinent configuration information 718 in the message 716,the handover controller 714 may include a fullConfig IE or some othertype of indication in the message 716 to indicate whether deltasignaling is applicable. As discussed herein, this IE may be aconventional fullConfig IE, a fullConfigMCG IE, or a fullConfigSCG IE.In scenarios where the handover controller does not include allpertinent configuration information 718 in the message 716, the handovercontroller 714 may omit the fullConfig IE from the message 716.

The communication controller 710 of the second device 704 includes ahandover controller 722 for controlling handover at the UE side astaught herein. For example, in response to an RRCConnectionReconfiguration message 716 received via the transceiver 712from the device 702, the handover controller 722 may determine whetherthe message 716 includes a fullConfig IE. If so, the device 704 mayobtain configuration information for the handover target from themessage 716. If the message 716 does not include a fullConfig IE, thedevice 704 may obtain configuration information to be reused for thehandover target from locally stored configuration information 724associated with the current source. For example, the configurationinformation 724 may include one or more of UE SDAP configurations ofDRBs, UE PDCP configurations of DRBs, UE physical layer configurations,UE MAC layer configurations, RLC configurations of DRBs, or acombination thereof. The configuration information 724 may include othertypes of configuration information in other examples.

FIG. 8 illustrates an example of a standalone NR to NR-DC handoveraccording to some examples. At block 802, a UE is in standalone NR(e.g., where the source cell is a 3GPP NG-RAN node). At block 804, theUE receives an RRC connection reconfiguration message. At block 806, theUE determines whether the message includes a fullConfig IE (e.g., aconventional fullConfig IE, a fullConfigMCG IE, or a fullConfigSCG IE).If so, at block 808, the UE uses configuration information from themessage to access the target cells. If the message does not include afullConfig IE (thereby indicating delta signaling), at block 810 the UEobtains at least a portion of the configuration information needed foraccessing the target cells from the configuration that the UE used foraccessing the source cell. Other information could be obtained from themessage as well in some examples. Once the UE obtains the configurationinformation needed to access the target cells, the UE performs a randomaccess directed to the target cells. In this case, the source cell maybe associated with a secondary cell group of the target cells (therebyfacilitating reuse of configuration information that was used foraccessing the source cell during standalone NR). Upon completion of thehandover, the UE is in NR-DC at block 812.

FIG. 9 illustrates an example of a standalone LTE to LTE-DC handoveraccording to some examples. At block 902, a UE is in standalone LTE(e.g., where the source cell is a 3GPP E-UTRA node). At block 904, theUE receives an RRC connection reconfiguration message. At block 906, theUE determines whether the message includes a fullConfig IE (e.g., aconventional fullConfig IE, a fullConfigMCG IE, or a fullConfigSCG IE).If so, at block 908, the UE uses configuration information from themessage to access the target cells. If the message does not include afullConfig IE (thereby indicating delta signaling), at block 910 the UEobtains at least a portion of the configuration information needed foraccessing the target cells from the configuration that the UE used foraccessing the source cell. Other information could be obtained from themessage as well in some examples. Once the UE obtains the configurationinformation needed to access the target cells, the UE performs a randomaccess directed to the target cells. In this case, the source cell maybe associated with a secondary cell group of the target cells (therebyfacilitating reuse of configuration information that was used foraccessing the source cell during standalone LTE). Upon completion of thehandover, the UE is in LTE-DC at block 912.

FIG. 10 illustrates an example of an EN-DC to standalone NR handoveraccording to some examples. At block 1002, a UE is in EN-DC (e.g., whereone source master cell group is associated with a 3GPP E-UTRA node andsource secondary cell group is associated with a 3GPP NG-RAN node). Atblock 1004, the UE receives an RRC connection reconfiguration message.At block 1006, the UE determines whether the message includes afullConfig IE (e.g., a conventional fullConfig IE, a fullConfigMCG IE,or a fullConfigSCG IE). If so, at block 1008, the UE uses configurationinformation from the message to access a target cell. If the messagedoes not include a fullConfig IE (thereby indicating delta signaling),at block 1010 the UE obtains at least a portion of the configurationinformation needed for accessing a target cell from the configurationthat the UE used for accessing the source cell. Other information couldbe obtained from the message as well in some examples. Once the UEobtains the configuration information needed to access the target cell,the UE performs a random access directed to the target cell. In thiscase, a source secondary group cell (e.g., a 3GPP NG-RAN node) may bethe target cell (thereby facilitating reuse of configuration informationthat was used for accessing the source cell during EN-DC). Uponcompletion of the handover, the UE is in standalone NR at block 1012.

FIG. 11 illustrates an example of an EN-DC to NR-DC handover accordingto some examples. At block 1102, a UE is in EN-DC (e.g., where onesource master cell group is associated with a 3GPP E-UTRA node andsource secondary cell group is associated with a 3GPP NG-RAN node). Atblock 1104, the UE receives an RRC connection reconfiguration message.At block 1106, the UE determines whether the message includes afullConfig IE (e.g., a conventional fullConfig IE, a fullConfigMCG IE,or a fullConfigSCG IE). If so, at block 1108, the UE uses configurationinformation from the message to access the target cells. If the messagedoes not include a fullConfig IE (thereby indicating delta signaling),at block 1110 the UE obtains at least a portion of the configurationinformation needed for accessing the target cells from the configurationthat the UE used for accessing the source cell. Other information couldbe obtained from the message as well in some examples. Once the UEobtains the configuration information needed to access the target cells,the UE performs a random access directed to the target cells. In thiscase, e.g., the target master cell group and the secondary cell groupare associated with 3GPP NG-RAN nodes, one of which may have beenassociated with the source secondary cell group (thereby facilitatingreuse of configuration information that was used for accessing thesource secondary cell group during EN-DC). Upon completion of thehandover, the UE is in NR-DC at block 1112.

FIG. 12 is a block diagram illustrating an example of a hardwareimplementation for a UE 1200 employing a processing system 1214. Forexample, the UE 1200 may be a device configured to wirelesslycommunicate with a base station, as discussed in any one or more ofFIGS. 1-11. In some implementations, the UE 1200 may correspond to anyof the UEs or scheduled entities shown in any of FIGS. 1, 2, 4, 5, 6, 7,18, and 19.

In accordance with various aspects of the disclosure, an element, or anyportion of an element, or any combination of elements may be implementedwith the processing system 1214. The processing system 1214 may includeone or more processors 1204. Examples of processors 1204 includemicroprocessors, microcontrollers, digital signal processors (DSPs),field programmable gate arrays (FPGAs), programmable logic devices(PLDs), state machines, gated logic, discrete hardware circuits, andother suitable hardware configured to perform the various functionalitydescribed throughout this disclosure. In various examples, the UE 1200may be configured to perform any one or more of the functions describedherein. That is, the processor 1204, as utilized in a UE 1200, may beused to implement any one or more of the processes and proceduresdescribed herein.

The processor 1204 may in some instances be implemented via a basebandor modem chip and in other implementations, the processor 1204 mayinclude a number of devices distinct and different from a baseband ormodem chip (e.g., in such scenarios as may work in concert to achievethe examples discussed herein). And as mentioned above, various hardwarearrangements and components outside of a baseband modem processor can beused in implementations, including RF-chains, power amplifiers,modulators, buffers, interleavers, adders/summers, etc.

In this example, the processing system 1214 may be implemented with abus architecture, represented generally by the bus 1202. The bus 1202may include any number of interconnecting buses and bridges depending onthe specific application of the processing system 1214 and the overalldesign constraints. The bus 1202 communicatively couples togethervarious circuits including one or more processors (represented generallyby the processor 1204), a memory 1205, and computer-readable media(represented generally by the computer-readable medium 1206). The bus1202 may also link various other circuits such as timing sources,peripherals, voltage regulators, and power management circuits, whichare well known in the art, and therefore, will not be described anyfurther. A bus interface 1208 provides an interface between the bus 1202and a transceiver 1210 and between the bus 1202 and an interface 1230.The transceiver 1210 provides a communication interface or means forcommunicating with various other apparatus over a wireless transmissionmedium. In some examples, the UE may include two or more transceivers1210, each configured to communicate with a respective network type(e.g., terrestrial or non-terrestrial). The interface 1230 provides acommunication interface or means of communicating with various otherapparatuses and devices (e.g., other devices housed within the sameapparatus as the UE or other external apparatuses) over an internal busor external transmission medium, such as an Ethernet cable. Dependingupon the nature of the apparatus, the interface 1230 may include a userinterface (e.g., keypad, display, speaker, microphone, joystick). Ofcourse, such a user interface is optional, and may be omitted in someexamples, such as an IoT device.

The processor 1204 is responsible for managing the bus 1202 and generalprocessing, including the execution of software stored on thecomputer-readable medium 1206. The software, when executed by theprocessor 1204, causes the processing system 1214 to perform the variousfunctions described below for any particular apparatus. Thecomputer-readable medium 1206 and the memory 1205 may also be used forstoring data that is manipulated by the processor 1204 when executingsoftware. For example, the memory 1205 may store configurationinformation 1215 (e.g., handover configuration information) used by theprocessor 1204 to control the handover of the UE 1200.

One or more processors 1204 in the processing system may executesoftware. Software shall be construed broadly to mean instructions,instruction sets, code, code segments, program code, programs,subprograms, software modules, applications, software applications,software packages, routines, subroutines, objects, executables, threadsof execution, procedures, functions, etc., whether referred to assoftware, firmware, middleware, microcode, hardware descriptionlanguage, or otherwise. The software may reside on a computer-readablemedium 1206.

The computer-readable medium 1206 may be a non-transitorycomputer-readable medium. A non-transitory computer-readable mediumincludes, by way of example, a magnetic storage device (e.g., hard disk,floppy disk, magnetic strip), an optical disk (e.g., a compact disc (CD)or a digital versatile disc (DVD)), a smart card, a flash memory device(e.g., a card, a stick, or a key drive), a random access memory (RAM), aread only memory (ROM), a programmable ROM (PROM), an erasable PROM(EPROM), an electrically erasable PROM (EEPROM), a register, a removabledisk, and any other suitable medium for storing software and/orinstructions that may be accessed and read by a computer. Thecomputer-readable medium 1206 may reside in the processing system 1214,external to the processing system 1214, or distributed across multipleentities including the processing system 1214. The computer-readablemedium 1206 may be embodied in a computer program product. By way ofexample, a computer program product may include a computer-readablemedium in packaging materials. Those skilled in the art will recognizehow best to implement the described functionality presented throughoutthis disclosure depending on the particular application and the overalldesign constraints imposed on the overall system.

The UE 1200 may be configured to perform any one or more of theoperations described herein (e.g., as described above in conjunctionwith FIGS. 1-11 and as described below in conjunction with FIGS. 13-14).In some aspects of the disclosure, the processor 1204, as utilized inthe UE 1200, may include circuitry configured for various functions.

The processor 1204 may include communication and processing circuitry1241. The communication and processing circuitry 1241 may be configuredto communicate with a base station, such as a gNB. The communication andprocessing circuitry 1241 may include one or more hardware componentsthat provide the physical structure that performs various processesrelated to wireless communication (e.g., signal reception and/or signaltransmission) as described herein. The communication and processingcircuitry 1241 may further include one or more hardware components thatprovide the physical structure that performs various processes relatedto signal processing (e.g., processing a received signal and/orprocessing a signal for transmission) as described herein. In someexamples, the communication and processing circuitry 1241 may includetwo or more transmit/receive chains, each configured to process signalsin a different RAT (or RAN) type. The communication and processingcircuitry 1241 may further be configured to execute communication andprocessing software 1251 included on the computer-readable medium 1206to implement one or more functions described herein.

In some examples, the communication and processing circuitry 1241 may beconfigured to receive and process downlink beamformed signals at ammWave frequency or a sub-6 GHz frequency via the transceiver 1210 andan antenna array 1220. For example, the communication and processingcircuitry 1241 may be configured to receive a respective referencesignal (e.g., SSB or CSI-RS) on each of a plurality of downlink beamsfrom the base station during a downlink beam sweep via at least onefirst antenna panel of the antenna array 1220. The communication andprocessing circuitry 1241 may further be configured to transmit a beammeasurement report to the base station.

In some examples, the communication and processing circuitry 1241 mayfurther be configured to generate and transmit uplink beamformed signalsat a mmWave frequency or a sub-6 GHz frequency via the transceiver 1210and the antenna array 1220. For example, the communication andprocessing circuitry 1241 may be configured to transmit a respectivereference signal (e.g., SRS or DMRS) on each of a plurality of uplinkbeams to the base station during an uplink beam sweep via at least onesecond antenna panel of the antenna array 1220.

The communication and processing circuitry 1241 may further beconfigured to generate and transmit a request to the base station. Forexample, the request may be included in a MAC-CE carried in a PUSCH, UCIin a PUCCH or PUSCH, a random access message, or an RRC message. Thecommunication and processing circuitry 1241 may further be configured togenerate and transmit a scheduling request (e.g., via UCI in a PUCCH) tothe base station to receive an uplink grant for a PUSCH.

The communication and processing circuitry 1241 may further beconfigured to generate and transmit an uplink signal on one or moreuplink transmit beams applied to the uplink signal. The uplink signalmay include, for example, a PUCCH, PUSCH, SRS, DMRS, or PRACH.

The communication and processing circuitry 1241 may further beconfigured to control the antenna array 1220 and the transceiver 1210 tosearch for and identify a plurality of downlink transmit beams during adownlink beam sweep. The communication and processing circuitry 1241 mayfurther be configured to obtain a plurality of beam measurements on eachof a plurality of downlink receive beams via the antenna array 1220 foreach of the identified downlink transmit beams. The communication andprocessing circuitry 1241 may further be configured to generate a beammeasurement report for transmission to the base station using thetransceiver 1210.

The communication and processing circuitry 1241 may further beconfigured to identify one or more selected uplink beam(s) based on thebeam measurements obtained from the downlink beam reference signals. Insome examples, the communication and processing circuitry 1241 may beconfigured to compare the respective reference signal received power(RSRP) or other beam measurement measured on each of the downlinkreceive beams for each of the serving downlink transmit beams toidentify the serving downlink receive beams and to further utilize theserving downlink receive beams as the selected uplink transmit beams.Each serving downlink receive beam may have the highest measured RSRP(or other beam measurement) for one of the downlink transmit beams.

The communication and processing circuitry 1241 may be configured togenerate one or more uplink transmit beams for transmission in an uplinkbeam sweep. Each uplink transmit beam may carry an uplink referencesignal (e.g., an SRS) for measurement by the base station. Thecommunication and processing circuitry 1241 may further be configured toidentify the selected uplink transmit beam(s) selected by the basestation based on the uplink beam measurements. For example, thecommunication and processing circuitry 1241 may be configured to receivean indication of the selected uplink transmit beam(s) from the basestation.

In some implementations where the communication involves receivinginformation, the communication and processing circuitry 1241 may obtaininformation from a component of the UE 1200 (e.g., from the transceiver1210 that receives the information via radio frequency signaling or someother type of signaling suitable for the applicable communicationmedium), process (e.g., decode) the information, and output theprocessed information. For example, the communication and processingcircuitry 1241 may output the information to another component of theprocessor 1204, to the memory 1205, or to the bus interface 1208. Insome examples, the communication and processing circuitry 1241 mayreceive one or more of signals, messages, other information, or anycombination thereof. In some examples, the communication and processingcircuitry 1241 may receive information via one or more channels. In someexamples, the communication and processing circuitry 1241 may includefunctionality for a means for receiving. In some examples, thecommunication and processing circuitry 1241 may include functionalityfor a means for decoding.

In some implementations where the communication involves sending (e.g.,transmitting) information, the communication and processing circuitry1241 may obtain information (e.g., from another component of theprocessor 1204, the memory 1205, or the bus interface 1208), process(e.g., encode) the information, and output the processed information.For example, the communication and processing circuitry 1241 may outputthe information to the transceiver 1210 (e.g., that transmits theinformation via radio frequency signaling or some other type ofsignaling suitable for the applicable communication medium). In someexamples, the communication and processing circuitry 1241 may send oneor more of signals, messages, other information, or any combinationthereof. In some examples, the communication and processing circuitry1241 may send information via one or more channels. In some examples,the communication and processing circuitry 1241 may includefunctionality for a means for sending (e.g., a means for transmitting).In some examples, the communication and processing circuitry 1241 mayinclude functionality for a means for encoding.

The communication and processing circuitry 1241 may includefunctionality for a means for using a source configuration (e.g., asdescribed in conjunction with the FIG. 7 and/or block 802 of FIG. 8and/or block 902 of FIG. 9 and/or block 1002 of FIG. 10 and/or block1102 of FIG. 11 and/or block 1302 of FIG. 13).

The processor 1204 may include handover configuration circuitry 1242configured to perform handover configuration-related operations asdiscussed herein (e.g., one or more of the operations described inconjunction with FIGS. 4-11). The handover configuration circuitry 1242may include functionality for a means for receiving a message associatedwith handover (e.g., as described in conjunction with the FIG. 7 and/orblock 804 of FIG. 8 and/or block 904 of FIG. 9 and/or block 1004 of FIG.10 and/or block 1104 of FIG. 11 and/or block 1304 of FIG. 13 and/orblock 1402 of FIG. 14). The handover configuration circuitry 1242 mayfurther be configured to execute handover configuration software 1252included on the computer-readable medium 1206 to implement one or morefunctions described herein.

The processor 1204 may include handover processing circuitry 1243configured to perform handover processing-related operations asdiscussed herein (e.g., one or more of the operations described inconjunction with FIGS. 4-11). The handover processing circuitry 1243 mayinclude functionality for a means for determining that the message doesnot include a full configuration indication (e.g., as described inconjunction with the FIG. 7 and/or block 806 of FIG. 8 and/or block 906of FIG. 9 and/or block 1006 of FIG. 10 and/or block 1106 of FIG. 11and/or block 1306 of FIG. 13 and/or block 1404 of FIG. 14). The handoverprocessing circuitry 1243 may include functionality for a means fordetermining that the message indicates that the wireless communicationdevice is to reuse a configuration (e.g., as described in conjunctionwith the FIG. 7 and/or block 806 of FIG. 8 and/or block 906 of FIG. 9and/or block 1006 of FIG. 10 and/or block 1106 of FIG. 11 and/or block1306 of FIG. 13 and/or block 1404 of FIG. 14). The handover processingcircuitry 1243 may include functionality for a means for configuring asecondary cell group (SCG) configuration (e.g., as described inconjunction with the FIG. 7 and/or block 810 of FIG. 8 and/or block 910of FIG. 9 and/or block 1010 of FIG. 10 and/or block 1110 of FIG. 11and/or block 1308 of FIG. 13 and/or block 1406 of FIG. 14). The handoverprocessing circuitry 1243 may include functionality for a means forobtaining a configuration (e.g., as described in conjunction with theFIG. 7 and/or block 810 of FIG. 8 and/or block 910 of FIG. 9 and/orblock 1010 of FIG. 10 and/or block 1110 of FIG. 11 and/or block 1308 ofFIG. 13 and/or block 1406 of FIG. 14). The handover processing circuitry1243 may include functionality for a means for abstaining from reusing aconfiguration (e.g., as described in conjunction with the FIG. 7 and/orblock 810 of FIG. 8 and/or block 910 of FIG. 9 and/or block 1010 of FIG.10 and/or block 1110 of FIG. 11 and/or block 1310 of FIG. 13 and/orblock 1408 of FIG. 14). The handover processing circuitry 1243 mayfurther be configured to execute handover processing software 1253included on the computer-readable medium 1206 to implement one or morefunctions described herein.

FIG. 13 is a flow chart illustrating an example process 1300 for awireless communication system in accordance with some aspects of thepresent disclosure. As described below, some or all illustrated featuresmay be omitted in a particular implementation within the scope of thepresent disclosure, and some illustrated features may not be requiredfor implementation of all examples. In some examples, the process 1300may be carried out by the UE 1200 illustrated in FIG. 12. In someexamples, the process 1300 may be carried out by any suitable apparatusor means for carrying out the functions or algorithm described below.

At block 1302, a wireless communication device (e.g., a UE) uses asource configuration for master cell group (MCG) connectivity (e.g., astandalone (SA) mode). For example, the communication and processingcircuitry 1241 and the transceiver 1210, shown and described above inconnection with FIG. 12, may establish a connection with an MCG andtransmit and receive data via the MCG.

At block 1304, the device receives a message associated with handover ofthe wireless communication device from the MCG connectivity to multipleradio access technology-dual connectivity (MR-DC) (e.g., handover to anon-standalone (NSA) mode). For example, the handover configurationcircuitry 1242 together with the communication and processing circuitry1241 and the transceiver 1210, shown and described above in connectionwith FIG. 12, may monitor a designated resource (e.g., a PDCCH or aPDSCH) for messages and parse a received message to determine whetherthe message indicates that the device is to be handed-over.

In some examples, the message may include a radio resource control (RRC)connection reconfiguration message. In some examples, the messageindicates whether a full SCG configuration is provided in the message.

In some examples, the MCG connectivity is associated with thirdgeneration partnership project (3GPP) new radio (NR) connectivity, andthe MR-DC is associated with 3GPP evolved universal terrestrial radioaccess (E-UTRA)-NR dual connectivity (EN-DC). In some examples, thewireless communication device is served by a third generationpartnership project (3GPP) next-generation-radio access network (NG-RAN)node during the MCG connectivity, and the 3GPP NG-RAN node is associatedwith the SCG for the MR-DC.

At block 1306, the device determines that the message does not include afull configuration indication. For example, the handover configurationcircuitry 1242, shown and described above in connection with FIG. 12,may determine that the message indicates that the device is to reuse atleast part of a configuration associated with the MCG connectivity forMR-DC. In some examples, the full configuration indication may include afullConfig information element (fullConfig IE).

At block 1308, the device configures a secondary cell group (SCG)configuration for the MR-DC by reusing the source configuration as aresult of the determination that the message does not include the fullconfiguration indication (of block 1306). For example, the handoverprocessing circuitry 1243 together with the communication and processingcircuitry 1241 and the transceiver 1210, shown and described above inconnection with FIG. 12, may retrieve configuration information for theMCG connectivity stored in memory and apply that configurationinformation for the MR-DC.

In some examples, the SCG configuration may include at least one of aservice data adaptation protocol (SDAP) configuration, a packet dataconvergence protocol (PDCP) configuration, a physical layerconfiguration, a medium access control (MAC) layer configuration, aradio link control (RLC) configuration, or any combination thereof.

At optional block 1310, the device may abstain from reusing a thirdconfiguration associated with the MCG connectivity for the sourceconfiguration as a result of the determination of block 1306. Forexample, the handover processing circuitry 1243 together with thecommunication and processing circuitry 1241 and the transceiver 1210,shown and described above in connection with FIG. 12, may determine thatsome configuration information for the MCG connectivity is not to beused for MR-DC and conduct handover operations accordingly. In someexamples, the third configuration may include at least one securityconfiguration.

In some examples, the process 1300 further includes determining that themessage may include an nr-SecondaryCellGroupConfig information elements(IE). In some examples, the process 1300 further includes applying aconfiguration provided in the IE.

In some examples, the wireless communication device may include a userequipment. In some examples, a process in accordance with the teachingsherein may include any combination of the above operations.

FIG. 14 is a flow chart illustrating an example process 1400 for awireless communication system in accordance with some aspects of thepresent disclosure. As described below, some or all illustrated featuresmay be omitted in a particular implementation within the scope of thepresent disclosure, and some illustrated features may not be requiredfor implementation of all examples. In some examples, the process 1400may be carried out by the UE 1200 illustrated in FIG. 12. In someexamples, the process 1400 may be carried out by any suitable apparatusor means for carrying out the functions or algorithm described below.

At block 1402, a wireless communication device (e.g., a UE) receives amessage associated with handover of the wireless communication devicefrom a first connectivity mode to a second connectivity mode, wherein atleast one of the first connectivity mode or the second connectivity modeis a multi-connectivity mode. For example, the handover configurationcircuitry 1242 together with the communication and processing circuitry1241 and the transceiver 1210, shown and described above in connectionwith FIG. 12, may monitor a designated resource (e.g., a PDCCH or aPDSCH) for messages and parse a received message to determine whetherthe message indicates that the device is to be handed-over.

In some examples, the message may include a radio resource control (RRC)connection reconfiguration message. In some examples, the message mayinclude a fullConfig information element (fullConfig IE). In someexamples, the message may include an indication of whether a full mastercell group (MCG) configuration is provided in the message. In someexamples, the message may include an indication of whether a fullsecondary cell group (SCG) configuration is provided in the message. Insome examples, the multi-connectivity mode may include adual-connectivity mode or a multi-radio access technology (multi-RAT)dual-connectivity mode.

At block 1404, the device determines that the message indicates that thewireless communication device is to reuse a first configurationassociated with the first connectivity mode for the second connectivitymode. For example, the handover configuration circuitry 1242 maydetermine that the message indicates that the device is to reuse atleast part of a configuration associated with the MCG connectivity forMR-DC. In some examples, the handover configuration circuitry 1242 maydetermine that the message does not include a full configurationindication (e.g., fullConfig IE). In some examples, the firstconfiguration may include a data radio bearer (DRB) configuration.

At block 1406, the device obtains a second configuration for the secondconnectivity mode based on the first configuration as a result of thedetermination of block 1404. For example, the handover processingcircuitry 1243 may retrieve configuration information for the MCGconnectivity stored in memory and apply that configuration informationfor the MR-DC.

At optional block 1408, the device may abstain from reusing a thirdconfiguration associated with the first connectivity mode for the secondconfiguration as a result of the determination that the messageindicates that the wireless communication device is to reuse the firstconfiguration (of block 1404). For example, the handover processingcircuitry 1243 together with the communication and processing circuitry1241 and the transceiver 1210, shown and described above in connectionwith FIG. 12, may determine that some configuration information for theMCG connectivity is not to be used for MR-DC and conduct handoveroperations accordingly. In some examples, the third configuration mayinclude at least one security configuration.

In some examples, the first connectivity mode may include thirdgeneration partnership project (3GPP) new radio (NR) standaloneconnectivity, and the second connectivity mode may include NR dualconnectivity (NR-DC). In some examples, the first configuration mayinclude at least one of a service data adaptation protocol (SDAP)configuration, a packet data convergence protocol (PDCP) configuration,a physical layer configuration, a medium access control (MAC) layerconfiguration, a radio link control (RLC) configuration, or anycombination thereof. In some examples, the wireless communication deviceis served by a 3GPP next-generation-radio access network (NG-RAN) nodeduring the first connectivity mode, and the 3GPP NG-RAN node isassociated with a secondary cell group (SCG) for the second connectivitymode.

In some examples, the first connectivity mode may include thirdgeneration partnership project (3GPP) long term evolution (LTE)standalone connectivity, and the second connectivity mode may includeLTE dual connectivity (LTE-DC). In some examples, the firstconfiguration may include at least one of a service data adaptationprotocol (SDAP) configuration, a packet data convergence protocol (PDCP)configuration, a physical layer configuration, a medium access control(MAC) layer configuration, a radio link control (RLC) configuration, orany combination thereof. In some examples, the wireless communicationdevice is served by a 3GPP evolved universal terrestrial radio access(E-UTRA) node during the first connectivity mode, and the 3GPP E-UTRAnode is associated with a secondary cell group (SCG) for the secondconnectivity mode.

In some examples, the first connectivity mode may include thirdgeneration partnership project (3GPP) evolved universal terrestrialradio access (E-UTRA)-NR dual connectivity (EN-DC), and the secondconnectivity mode may include NR standalone connectivity. In someexamples, the first configuration may include at least one of a servicedata adaptation protocol (SDAP) configuration, a packet data convergenceprotocol (PDCP) configuration, a physical layer configuration, a mediumaccess control (MAC) layer configuration, a radio link control (RLC)configuration, or any combination thereof. In some examples, a secondarycell group (SCG) for the first connectivity mode may include a 3GPPnext-generation-radio access network (NG-RAN) node, and the wirelesscommunication device is served by the 3GPP NG-RAN node during the secondconnectivity mode.

In some examples, the first connectivity mode may include thirdgeneration partnership project (3GPP) 3GPP) evolved universalterrestrial radio access (E-UTRA)-NR dual connectivity (EN-DC), and thesecond connectivity mode may include NR dual connectivity (NR-DC). Insome examples, the first configuration may include at least one of aservice data adaptation protocol (SDAP) configuration, a packet dataconvergence protocol (PDCP) configuration, a physical layerconfiguration, a medium access control (MAC) layer configuration, aradio link control (RLC) configuration, or any combination thereof. Insome examples, a secondary cell group (SCG) for the first connectivitymode may include a 3GPP next-generation-radio access network (NG-RAN)node, and the 3GPP NG-RAN node may include a master cell group (MCG)during the second connectivity mode.

In some examples, the first connectivity mode may include thirdgeneration partnership project (3GPP) new radio (NR) connectivity, andthe second connectivity mode may include 3GPP evolved universalterrestrial radio access (E-UTRA)-NR dual connectivity (EN-DC). In someexamples, the first configuration may include at least one of a servicedata adaptation protocol (SDAP) configuration, a packet data convergenceprotocol (PDCP) configuration, a physical layer configuration, a mediumaccess control (MAC) layer configuration, a radio link control (RLC)configuration, or any combination thereof. In some examples, thewireless communication device is served by a 3GPP next-generation-radioaccess network (NG-RAN) node during the first connectivity mode, and the3GPP NG-RAN node is associated with a secondary cell group (SCG) duringthe second connectivity mode.

In some examples, the wireless communication device may include a userequipment. In some examples, a process in accordance with the teachingsherein may include any combination of the above operations.

FIG. 15 is a conceptual diagram illustrating an example of a hardwareimplementation for base station (BS) 1500 employing a processing system1514. In some implementations, the BS 1500 may correspond to any of theBSs (e.g., gNBs) or scheduling entities shown in any of FIGS. 1, 2, 4,5, 6, 7, 20, and 21.

In accordance with various aspects of the disclosure, an element, or anyportion of an element, or any combination of elements may be implementedwith the processing system 1514. The processing system may include oneor more processors 1504. The processing system 1514 may be substantiallythe same as the processing system 1214 illustrated in FIG. 12, includinga bus interface 1508, a bus 1502, memory 1505, a processor 1504, and acomputer-readable medium 1506. The memory 1505 may store configurationinformation 1515 (e.g., handover configuration information) used by theprocessor 1504 to control the handover of a UE. Furthermore, the BS 1500may include an interface 1530 (e.g., a network interface) that providesa means for communicating with at least one other apparatus within acore network and with at least one radio access network.

The BS 1500 may be configured to perform any one or more of theoperations described herein (e.g., as described above in conjunctionwith FIGS. 1-11 and as described below in conjunction with FIGS. 16-17).In some aspects of the disclosure, the processor 1504, as utilized inthe BS 1500, may include circuitry configured for various functions.

The processor 1504 may be configured to generate, schedule, and modify aresource assignment or grant of time-frequency resources (e.g., a set ofone or more resource elements). For example, the processor 1504 mayschedule time-frequency resources within a plurality of time divisionduplex (TDD) and/or frequency division duplex (FDD) subframes, slots,and/or mini-slots to carry user data traffic and/or control informationto and/or from multiple UEs.

The processor 1504 may be configured to schedule resources for thetransmission of downlink reference signals (e.g., SSBs or CSI-RSs) on aplurality of downlink beams for a downlink beam sweep in accordance witha selected downlink beam sweep type and selected number of downlinkreference signal resources indicated in a request for uplink beamrefinement received from a UE. The processor 1504 may further beconfigured to schedule resources for the uplink transmission of uplinkreference signals (e.g., SRSs) on a plurality of uplink beams for anuplink beam sweep in accordance with a selected beam sweep type andselected number of uplink reference signal resources indicated in therequest. The processor 1504 may further be configured to scheduleresources that may be utilized by the UE to transmit the request. Forexample, the uplink beam refinement request resources may includeresources scheduled for transmission of a PUCCH, PUSCH, PRACH occasionor RRC message. In some examples, the processor 1504 may be configuredto schedule PUSCH resources for the uplink beam refinement request inresponse to receiving a scheduling request from the UE.

The processor 1504 may further be configured to schedule resources forthe transmission of an uplink signal. In some examples, the resourcesmay be associated with one or more uplink transmit beams and one or morecorresponding receive beams applied to the uplink signal (e.g., based onthe uplink BPLs) based on an indication of the uplink signal associatedwith the one or more uplink transmit beams included in the request. Insome examples, the resources may be associated with an uplinktransmission scheme indicating a number of uplink transmit beams to beutilized for the uplink signal, a number of repetitions per uplinktransmit beam of the uplink signal, and a multiplexing scheme when morethan one uplink transmit beam is used to transmit the uplink signal.

In some aspects of the disclosure, the processor 1504 may includecommunication and processing circuitry 1541. The communication andprocessing circuitry 1544 may be configured to communicate with a UE.The communication and processing circuitry 1541 may include one or morehardware components that provide the physical structure that performsvarious processes related to communication (e.g., signal receptionand/or signal transmission) as described herein. The communication andprocessing circuitry 1541 may further include one or more hardwarecomponents that provide the physical structure that performs variousprocesses related to signal processing (e.g., processing a receivedsignal and/or processing a signal for transmission) as described herein.The communication and processing circuitry 1541 may further beconfigured to execute communication and processing software 1551included on the computer-readable medium 1506 to implement one or morefunctions described herein.

In some examples, the communication and processing circuitry 1541 may beconfigured to receive and process uplink beamformed signals at a mmWavefrequency or a sub-6 GHz frequency via the transceiver 1510 and anantenna array 1520. For example, the communication and processingcircuitry 1541 may be configured to receive a respective referencesignal (e.g., SRS or DMRS) on each of a plurality of uplink beams fromthe UE during an uplink beam sweep.

In some examples, the communication and processing circuitry 1541 mayfurther be configured to generate and transmit downlink beamformedsignals at a mmWave frequency or a sub-6 GHz frequency via thetransceiver 1510 and the antenna array 1520. For example, thecommunication and processing circuitry 1541 may be configured totransmit a respective downlink reference signal (e.g., SSB or CSI-RS) oneach of a plurality of downlink beams to the UE during a downlink beamsweep via at least one first antenna panel of the antenna array 1520.The communication and processing circuitry 1541 may further beconfigured to receive a beam measurement report from the UE.

The communication and processing circuitry 1541 may further beconfigured to receive a request from the UE. For example, the requestmay be included in a MAC-CE carried in a PUSCH, UCI in a PUCCH or PUSCH,a random access message, or an RRC message. The communication andprocessing circuitry 1541 may further be configured to receive ascheduling request (e.g., via UCI in a PUCCH) from the UE for an uplinkgrant for the PUSCH carrying the MAC-CE.

The communication and processing circuitry 1541 may further beconfigured to receive an uplink signal on one or more uplink receivebeams via one or more uplink transmit beams applied to the uplinksignal. For example, the communication and processing circuitry 1541 maybe configured to receive the uplink signal on one or more uplink receivebeams via at least one second antenna panel of the antenna array 1520.The uplink signal may include, for example, a PUCCH, PUSCH, SRS, DMRS,or PRACH.

The communication and processing circuitry 1541 may further beconfigured to control the antenna array 1520 and transceiver 1510 togenerate a plurality of downlink transmit beams during a downlink beamsweep. The communication and processing circuitry 1541 may further beconfigured to receive a beam measurement report from the UE using thecommunication and processing circuitry 1544. The communication andprocessing circuitry 1541 may further be configured to identify one ormore selected uplink beam(s) based on the beam measurements. In someexamples, the communication and processing circuitry 1541 may beconfigured to compare the respective RSRP (or other beam measurement)measured on each of the downlink receive beams for each of the servingdownlink transmit beams to identify the serving downlink receive beamsand to further identify the serving downlink receive beams as theselected uplink transmit beams. Each serving downlink receive beam mayhave the highest measured RSRP (or other beam measurement) for one ofthe downlink transmit beams.

The communication and processing circuitry 1541 may be configured toreceive one or more uplink transmit beams in an uplink beam sweep. Eachuplink transmit beam may carry an uplink reference signal (e.g., an SRS)for measurement by the communication and processing circuitry 1541. Thecommunication and processing circuitry 1541 may further be configured toobtain a plurality of beam measurements on each of a plurality of uplinkreceive beams of the antenna array 1520 for each of the uplink transmitbeams. The communication and processing circuitry 1541 may further beconfigured to select the selected uplink transmit beam(s) andcorresponding uplink receive beams forming respective uplink BPLs basedon the uplink beam measurements.

In some implementations wherein the communication involves receivinginformation, the communication and processing circuitry 1541 may obtaininformation from a component of the BS 1500 (e.g., from the transceiver1510 that receives the information via radio frequency signaling or someother type of signaling suitable for the applicable communicationmedium), process (e.g., decode) the information, and output theprocessed information. For example, the communication and processingcircuitry 1541 may output the information to another component of theprocessor 1504, to the memory 1505, or to the bus interface 1508. Insome examples, the communication and processing circuitry 1541 mayreceive one or more of signals, messages, other information, or anycombination thereof. In some examples, the communication and processingcircuitry 1541 may receive information via one or more channels. In someexamples, the communication and processing circuitry 1541 may includefunctionality for a means for receiving. In some examples, thecommunication and processing circuitry 1541 may include functionalityfor a means for decoding.

In some implementations wherein the communication involves sending(e.g., transmitting) information, the communication and processingcircuitry 1541 may obtain information (e.g., from another component ofthe processor 1504, the memory 1505, or the bus interface 1508), process(e.g., encode) the information, and output the processed information.For example, the communication and processing circuitry 1541 may outputthe information to the transceiver 1510 (e.g., that transmits theinformation via radio frequency signaling or some other type ofsignaling suitable for the applicable communication medium). In someexamples, the communication and processing circuitry 1541 may send oneor more of signals, messages, other information, or any combinationthereof. In some examples, the communication and processing circuitry1541 may send information via one or more channels. In some examples,the communication and processing circuitry 1541 may includefunctionality for a means for sending (e.g., a means for transmitting).In some examples, the communication and processing circuitry 1541 mayinclude functionality for a means for encoding.

The processor 1504 may include handover configuration circuitry 1542configured to perform handover configuration-related operations asdiscussed herein (e.g., one or more of the operations described inconjunction with FIGS. 4-11). The handover configuration circuitry 1542may include functionality for a means for generating a message thatindicates whether delta signaling is applicable (e.g., as described inconjunction with the FIG. 7 and/or block 804 of FIG. 8 and/or block 904of FIG. 9 and/or block 1004 of FIG. 10 and/or block 1104 of FIG. 11and/or block 1604 of FIG. 16 and/or block 1704 of FIG. 17). The handoverconfiguration circuitry 1542 may include functionality for a means forsending a message (e.g., as described in conjunction with the FIG. 7and/or block 804 of FIG. 8 and/or block 904 of FIG. 9 and/or block 1004of FIG. 10 and/or block 1104 of FIG. 11 and/or block 1606 of FIG. 16and/or block 1706 of FIG. 17). The handover configuration circuitry 1542may further be configured to execute handover configuration software1552 included on the computer-readable medium 1506 to implement one ormore functions described herein.

The processor 1504 may include handover processing circuitry 1543configured to perform handover processing-related operations asdiscussed herein (e.g., one or more of the operations described inconjunction with FIGS. 4-11). The handover processing circuitry 1543 mayinclude functionality for a means for determining that a UE is to behanded-over (e.g., as described in conjunction with the FIG. 7 and/orblock 804 of FIG. 8 and/or block 904 of FIG. 9 and/or block 1004 of FIG.10 and/or block 1104 of FIG. 11 and/or block 1602 of FIG. 16 and/orblock 1702 of FIG. 17). The handover processing circuitry 1543 mayfurther be configured to execute handover processing software 1553included on the computer-readable medium 1506 to implement one or morefunctions described herein.

FIG. 16 is a flow chart illustrating an example process 1600 forwireless communication in accordance with some aspects of the presentdisclosure. As described below, some or all illustrated features may beomitted in a particular implementation within the scope of the presentdisclosure, and some illustrated features may not be required forimplementation of all examples. In some examples, the process 1600 maybe carried out by the BS 1500 illustrated in FIG. 15. In some examples,the process 1600 may be carried out by any suitable apparatus or meansfor carrying out the functions or algorithm described below.

At block 1602, a device (e.g., a BS) determines that a wirelesscommunication device is to be handed-over from master cell groupconnectivity (e.g., a standalone (SA) mode) to multiple radio accesstechnology-dual connectivity (MR-DC) (e.g., handover to a non-standalone(NSA) mode). For example, the handover processing circuitry 1543together with the communication and processing circuitry 1541 and thetransceiver 1510, shown and described above in connection with FIG. 15,may determine that a UE needs to access service (e.g., VoIP) that is notprovided by the MCG connectivity.

In some examples, the MCG connectivity is associated with thirdgeneration partnership project (3GPP) new radio (NR) connectivity, andthe MR-DC is associated with 3GPP evolved universal terrestrial radioaccess (E-UTRA)-NR dual connectivity (EN-DC). In some examples, thewireless communication device is served by a third generationpartnership project (3GPP) next-generation-radio access network (NG-RAN)node during the MCG connectivity, and the 3GPP NG-RAN node is associatedwith the SCG for the MR-DC.

At block 1604, the device generates a message as a result of thedetermination of block 1602. The message indicates whether deltasignaling is applicable to a secondary cell group (SCG) configurationfor the MR-DC. For example, the handover configuration circuitry 1542,shown and described above in connection with FIG. 15, may generate amessage that indicates that the device is to reuse a first configurationassociated with the MCG connectivity for the MR-DC. In some examples,the handover configuration circuitry 1242 may generate a message thatdoes not include a fullConfig IE.

In some examples, the delta signaling relates to the wirelesscommunication device reusing a source configuration associated with theMCG connectivity for the SCG configuration for the MR-DC. For example,the delta signaling may notify the wireless communication device toreuse a source configuration associated with the MCG connectivity forthe SCG configuration for the MR-DC.

In some examples, the source configuration may include at least one of aservice data adaptation protocol configuration (e.g., SDAPconfigurations of DRBs), a packet data convergence protocolconfiguration (e.g., PDCP configurations of DRBs), a physical layerconfiguration, a medium access control (MAC) layer configuration, aradio link control configuration (e.g., RLC configurations of DRBs), orany combination thereof.

In some examples, the delta signaling further relates to the wirelesscommunication device abstaining from reusing a third configurationassociated with the MCG connectivity for the SCG configuration for theMR-DC. For example, the delta signaling may notify the wirelesscommunication device to abstain from reusing a third configurationassociated with the MCG connectivity for the SCG configuration for theMR-DC. In some examples, the third configuration may include at leastone security configuration.

At block 1606, the device sends the message to the wirelesscommunication device. For example, the handover configuration circuitry1542 together with the communication and processing circuitry 1541 andthe transceiver 1510, shown and described above in connection with FIG.15, may encode and transmit the message on a designated resource (e.g.,an PDCCH or PDSCH) for a UE.

In some examples, the message may include a radio resource control (RRC)connection reconfiguration message. In some examples, the message mayinclude a fullConfig information element (fullConfig IE). In someexamples, the message indicates whether a full SCG configuration isprovided in the message.

In some examples, the wireless communication device may include a userequipment. In some examples, a process in accordance with the teachingsherein may include any combination of the above operations.

FIG. 17 is a flow chart illustrating an example process 1700 forwireless communication in accordance with some aspects of the presentdisclosure. As described below, some or all illustrated features may beomitted in a particular implementation within the scope of the presentdisclosure, and some illustrated features may not be required forimplementation of all examples. In some examples, the process 1700 maybe carried out by the BS 1500 illustrated in FIG. 15. In some examples,the process 1700 may be carried out by any suitable apparatus or meansfor carrying out the functions or algorithm described below.

At block 1702, a device (e.g., a BS) determines that a wirelesscommunication device is to be handed-over from a first connectivity modeto a second connectivity mode, wherein at least one of the firstconnectivity mode or the second connectivity mode is amulti-connectivity mode. For example, the handover processing circuitry1543 together with the communication and processing circuitry 1541 andthe transceiver 1510, shown and described above in connection with FIG.15, may determine that a UE needs to access service (e.g., VoIP) that isnot provided by the MCG connectivity.

In some examples, the multi-connectivity mode may include adual-connectivity mode or a multi-radio access technology (multi-RAT)dual-connectivity mode.

At block 1704, the device generates a message as a result of thedetermination of block 1702. The message may include an indication ofwhether the wireless communication device is to reuse a configurationassociated with the first connectivity mode for the second connectivitymode. For example, the handover configuration circuitry 1542, shown anddescribed above in connection with FIG. 15, may generate a message thatindicates that the device is to reuse a first configuration associatedwith the first connectivity mode for the second connectivity mode. Forexample, the handover configuration circuitry 1242 may generate themessage to indicate that the device is to reuse at least part of aconfiguration associated with the MCG connectivity for MR-DC.

In some examples, the message may include a radio resource control (RRC)connection reconfiguration message. In some examples, the indication mayinclude a fullConfig information element (IE). In some examples, theconfiguration may include a data radio bearer (DRB) configuration.

In some examples, the indication further indicates that the wirelesscommunication device is to abstain from reusing a third configurationassociated with the first connectivity mode for the second connectivitymode. In some examples, the third configuration may include at least onesecurity configuration.

In some examples, the indication indicates whether a full master cellgroup (MCG) configuration is provided in the message. In some examples,the indication indicates whether a full secondary cell group (SCG)configuration is provided in the message.

At block 1706, the device sends the message to the wirelesscommunication device. For example, the handover configuration circuitry1542 together with the communication and processing circuitry 1541 andthe transceiver 1510, shown and described above in connection with FIG.15, may encode and transmit the message on a designated resource (e.g.,an PDCCH or PDSCH) for a UE.

In some examples, the first connectivity mode may include thirdgeneration partnership project (3GPP) new radio (NR) standaloneconnectivity, and the second connectivity mode may include NR dualconnectivity (NR-DC). In some examples, the configuration may include atleast one of a service data adaptation protocol (SDAP) configuration, apacket data convergence protocol (PDCP) configuration, a physical layerconfiguration, a medium access control (MAC) layer configuration, aradio link control (RLC) configuration, or any combination thereof. Insome examples, the wireless communication device is served by a 3GPPnext-generation-radio access network (NG-RAN) node during the firstconnectivity mode, and the 3GPP NG-RAN node is associated with asecondary cell group (SCG) for the second connectivity mode.

In some examples, the first connectivity mode may include thirdgeneration partnership project (3GPP) long term evolution (LTE)standalone connectivity, and the second connectivity mode may includeLTE dual connectivity (LTE-DC). In some examples, the configuration mayinclude at least one of a service data adaptation protocol (SDAP)configuration, a packet data convergence protocol (PDCP) configuration,a physical layer configuration, a medium access control (MAC) layerconfiguration, a radio link control (RLC) configuration, or anycombination thereof. In some examples, the wireless communication deviceis served by a 3GPP evolved universal terrestrial radio access (E-UTRA)node during the first connectivity mode, and the 3GPP E-UTRA node isassociated with a secondary cell group (SCG) for the second connectivitymode.

In some examples, the first connectivity mode may include thirdgeneration partnership project (3GPP) evolved universal terrestrialradio access (E-UTRA)-NR dual connectivity (EN-DC), and the secondconnectivity mode may include NR standalone connectivity. In someexamples, the configuration may include at least one of a service dataadaptation protocol (SDAP) configuration, a packet data convergenceprotocol (PDCP) configuration, a physical layer configuration, a mediumaccess control (MAC) layer configuration, a radio link control (RLC)configuration, or any combination thereof. In some examples, a secondarycell group (SCG) for the first connectivity mode may include a 3GPPnext-generation-radio access network (NG-RAN) node, and the wirelesscommunication device is served by the 3GPP NG-RAN node during the secondconnectivity mode.

In some examples, the first connectivity mode may include thirdgeneration partnership project (3GPP) 3GPP) evolved universalterrestrial radio access (E-UTRA)-NR dual connectivity (EN-DC), and thesecond connectivity mode may include NR dual connectivity (NR-DC). Insome examples, the configuration may include at least one of a servicedata adaptation protocol (SDAP) configuration, a packet data convergenceprotocol (PDCP) configuration, a physical layer configuration, a mediumaccess control (MAC) layer configuration, a radio link control (RLC)configuration, or any combination thereof. In some examples, a secondarycell group (SCG) for the first connectivity mode may include a 3GPPnext-generation-radio access network (NG-RAN) node, and the 3GPP NG-RANnode may include a master cell group (MCG) during the secondconnectivity mode.

In some examples, the first connectivity mode may include thirdgeneration partnership project (3GPP) new radio (NR) connectivity, andthe second connectivity mode may include 3GPP evolved universalterrestrial radio access (E-UTRA)-NR dual connectivity (EN-DC). In someexamples, the configuration may include at least one of a service dataadaptation protocol (SDAP) configuration, a packet data convergenceprotocol (PDCP) configuration, a physical layer configuration, a mediumaccess control (MAC) layer configuration, a radio link control (RLC)configuration, or any combination thereof. In some examples, thewireless communication device is served by a 3GPP next-generation-radioaccess network (NG-RAN) node during the first connectivity mode, and the3GPP NG-RAN node is associated with a secondary cell group (SCG) duringthe second connectivity mode.

In some examples, the wireless communication device may include a userequipment. In some examples, a process in accordance with the teachingsherein may include any combination of the above operations.

FIG. 18 illustrates a block diagram of an example hardwareimplementation of a wireless communication device 1800 configured tocommunicate according to some aspects. The device 1800 could embody orbe implemented within a UE, a wireless communication device, a basestation (BS), a gNB, a transmit receive point (TRP), an eNode B (eNB), aCPE, or some other type of device that supports wireless communication.In various implementations, the device 1800 could embody or beimplemented within an access terminal, an access point, or some othertype of device. In various implementations, the device 1800 could embodyor be implemented within a server, a personal computer, a mobile phone,a smart phone, a tablet, a portable computer, a sensor, an alarm, avehicle, a machine, an entertainment device, a medical device, or anyother electronic device having circuitry. The device 1800 may correspondat least in some aspect to, for example, any of the UEs or scheduledentities shown in any of FIGS. 1, 2, 4, 5, 6, 7, 12, and 19.

The device 1800 includes a communication interface 1802 (e.g., at leastone transceiver), a storage medium 1804, a user interface 1806, a memorydevice 1808 (e.g., storing configuration information 1818), and aprocessing circuit 1810 (e.g., at least one processor). In variousimplementations, the user interface 1806 may include one or more of akeypad, a display, a speaker, a microphone, a touchscreen display, ofsome other circuitry for receiving an input from or sending an output toa user. The communication interface 1802 may be coupled to one or moreantennas 1812, and may include a transmitter 1814 and a receiver 1816.In general, the components of FIG. 18 may be similar to correspondingcomponents of the UE 1200 of FIG. 12.

The processing circuit 1810 may be adapted to perform any or all of thefeatures, processes, functions, operations and/or routines for any orall of the devices described herein. For example, the processing circuit1810 may be configured to perform any of the steps, functions, and/orprocesses described with respect to FIGS. 1-11 and 13. As used herein,the term “adapted” in relation to the processing circuit 1810 may referto the processing circuit 1810 being one or more of configured, used,implemented, and/or programmed to perform a particular process,function, operation and/or routine according to various featuresdescribed herein.

The processing circuit 1810 may be a specialized processor, such as anapplication specific integrated circuit (ASIC) that serves as a meansfor (e.g., structure for) carrying out any one of the operationsdescribed in conjunction with FIGS. 1-11 and 13. The processing circuit1810 may serve as one example of a means for transmitting and/or a meansfor receiving. In various implementations, the processing circuit 1810may provide and/or incorporate, at least in part, the functionalitydescribed above for the second device 704 (e.g., the communicationcontroller 710) of FIG. 7.

According to at least one example of the device 1800, the processingcircuit 1810 may include one or more of a circuit/module for using 1820,a circuit/module for receiving 1822, a circuit/module for determining1824, a circuit/module for configuring 1826, a circuit/module forabstaining 1828, or a circuit/module for applying 1830. In variousimplementations, the circuit/module for using 1820, the circuit/modulefor receiving 1822, the circuit/module for determining 1824, thecircuit/module for configuring 1826, the circuit/module for abstaining1828, or the circuit/module for applying 1830 may provide and/orincorporate, at least in part, the functionality described above for thesecond device 704 (e.g., the communication controller 710) of FIG. 7.

As mentioned above, programming stored by the storage medium 1804, whenexecuted by the processing circuit 1810, causes the processing circuit1810 to perform one or more of the various functions and/or processoperations described herein. For example, the programming may cause theprocessing circuit 1810 to perform the various functions, steps, and/orprocesses described herein with respect to FIGS. 1-11 and 13 in variousimplementations. As shown in FIG. 18, the storage medium 1804 mayinclude one or more of code for using 1840, code for receiving 1842,code for determining 1244, code for configuring 1846, code forabstaining 1848, or code for applying 1850. In various implementations,the code for using 1840, the code for receiving 1842, the code fordetermining 1844, the code for configuring 1846, the code for abstaining1848, or the code for applying 1850 may be executed or otherwise used toprovide the functionality described herein for the circuit/module forusing 1820, the circuit/module for receiving 1822, the circuit/modulefor determining 1824, the circuit/module for configuring 1826, thecircuit/module for abstaining 1828, or the circuit/module for applying1830.

In some examples, the circuit/module for using 1820 of FIG. 18 (e.g.,the communication controller 710 of FIG. 7) performs the operations ofblock 1302 and/or other similar operations as taught herein. In someexamples, the code for using 1840 of FIG. 18 is executed to perform theoperations of block 1302 and/or other similar operations as taughtherein.

In some examples, the circuit/module for receiving 1822 of FIG. 18(e.g., the communication controller 710 of FIG. 7 performs theoperations of block 1304 and/or other similar operations as taughtherein. In some examples, the code for receiving 1842 of FIG. 18 isexecuted to perform the operations of block 1304 and/or other similaroperations as taught herein.

In some examples, the circuit/module for determining 1824 of FIG. 18(e.g., the handover controller 722 of FIG. 7) performs the operations ofblock 1306 and/or other similar operations as taught herein. In someexamples, the code for determining 1844 of FIG. 18 is executed toperform the operations of block 1306 and/or other similar operations astaught herein.

In some examples, the circuit/module for configuring 1826 of FIG. 18(e.g., the handover controller 722 of FIG. 7) performs the operations ofblock 1308 and/or other similar operations as taught herein. In someexamples, the code for configuring 1846 of FIG. 18 is executed toperform the operations of block 1308 and/or other similar operations astaught herein.

In some examples, the circuit/module for abstaining 1828 of FIG. 18(e.g., the handover controller 722 of FIG. 7) performs the operations ofblock 1310 and/or other similar operations as taught herein. In someexamples, the code for abstaining 1848 of FIG. 18 is executed to performthe operations of block 1310 and/or other similar operations as taughtherein.

FIG. 19 illustrates a block diagram of an example hardwareimplementation of a wireless communication device 1900 configured tocommunicate according to some aspects. The device 1900 could embody orbe implemented within a UE, a wireless communication device, a basestation (BS), a gNB, a transmit receive point (TRP), an eNode B (eNB), aCPE, or some other type of device that supports wireless communication.In various implementations, the device 1900 could embody or beimplemented within an access terminal, an access point, or some othertype of device. In various implementations, the device 1900 could embodyor be implemented within a server, a personal computer, a mobile phone,a smart phone, a tablet, a portable computer, a sensor, an alarm, avehicle, a machine, an entertainment device, a medical device, or anyother electronic device having circuitry. The device 1900 may correspondat least in some aspect to, for example, any of the UEs or scheduledentities shown in any of FIGS. 1, 2, 4, 5, 6, 7, 12, and 18.

The device 1900 includes a communication interface 1902 (e.g., at leastone transceiver), a storage medium 1904, a user interface 1906, a memorydevice 1908 (e.g., storing configuration information 1918), and aprocessing circuit 1910 (e.g., at least one processor). In variousimplementations, the user interface 1906 may include one or more of akeypad, a display, a speaker, a microphone, a touchscreen display, ofsome other circuitry for receiving an input from or sending an output toa user. The communication interface 1902 may be coupled to one or moreantennas 1912, and may include a transmitter 1914 and a receiver 1916.In general, the components of FIG. 19 may be similar to correspondingcomponents of the UE 1200 of FIG. 12.

The processing circuit 1910 may be adapted to perform any or all of thefeatures, processes, functions, operations and/or routines for any orall of the devices described herein. For example, the processing circuit1910 may be configured to perform any of the steps, functions, and/orprocesses described with respect to FIGS. 1-11 and 14. As used herein,the term “adapted” in relation to the processing circuit 1910 may referto the processing circuit 1910 being one or more of configured, used,implemented, and/or programmed to perform a particular process,function, operation and/or routine according to various featuresdescribed herein.

The processing circuit 1910 may be a specialized processor, such as anapplication specific integrated circuit (ASIC) that serves as a meansfor (e.g., structure for) carrying out any one of the operationsdescribed in conjunction with FIGS. 1-11 and 14. The processing circuit1910 may serve as one example of a means for transmitting and/or a meansfor receiving. In various implementations, the processing circuit 1910may provide and/or incorporate, at least in part, the functionalitydescribed above for the second device 704 (e.g., the communicationcontroller 710) of FIG. 7.

According to at least one example of the device 1900, the processingcircuit 1910 may include one or more of a circuit/module for receiving1920, a circuit/module for determining 1922, a circuit/module forobtaining 1924, or a circuit/module for abstaining 1926. In variousimplementations, the circuit/module for receiving 1920, thecircuit/module for determining 1922, the circuit/module for obtaining1924, or the circuit/module for abstaining 1926 may provide and/orincorporate, at least in part, the functionality described above for thesecond device 704 (e.g., the communication controller 710) of FIG. 7.

As mentioned above, programming stored by the storage medium 1904, whenexecuted by the processing circuit 1910, causes the processing circuit1910 to perform one or more of the various functions and/or processoperations described herein. For example, the programming may cause theprocessing circuit 1910 to perform the various functions, steps, and/orprocesses described herein with respect to FIGS. 1-11 and 14 in variousimplementations. As shown in FIG. 19, the storage medium 1904 mayinclude one or more of code for receiving 1940, code for determining1942, code for obtaining 1944, or code for abstaining 1946. In variousimplementations, the code for receiving 1940, the code for determining1942, the code for obtaining 1944, or the code for abstaining 1946 maybe executed or otherwise used to provide the functionality describedherein for the circuit/module for receiving 1920, the circuit/module fordetermining 1922, the circuit/module for obtaining 1924, or thecircuit/module for abstaining 1926.

In some examples, the circuit/module for receiving 1920 of FIG. 19(e.g., the communication controller 710 of FIG. 7) performs theoperations of block 1402 and/or other similar operations as taughtherein. In some examples, the code for receiving 1940 of FIG. 19 isexecuted to perform the operations of block 1402 and/or other similaroperations as taught herein.

In some examples, the circuit/module for determining 1922 of FIG. 19(e.g., the handover controller 722 of FIG. 7) performs the operations ofblock 1404 and/or other similar operations as taught herein. In someexamples, the code for determining 1942 of FIG. 19 is executed toperform the operations of block 1404 and/or other similar operations astaught herein.

In some examples, the circuit/module for obtaining 1924 of FIG. 19(e.g., the handover controller 722 of FIG. 7) performs the operations ofblock 1406 and/or other similar operations as taught herein. In someexamples, the code for obtaining 1944 of FIG. 19 is executed to performthe operations of block 1406 and/or other similar operations as taughtherein.

In some examples, the circuit/module for abstaining 1926 of FIG. 19(e.g., the handover controller 722 of FIG. 7) performs the operations ofblock 1408 and/or other similar operations as taught herein. In someexamples, the code for abstaining 1946 of FIG. 19 is executed to performthe operations of block 1408 and/or other similar operations as taughtherein.

FIG. 20 illustrates a block diagram of an example hardwareimplementation of a wireless communication device 2000 configured tocommunicate according to some aspects. The device 2000 could embody orbe implemented within a gNB, a transmit receive point (TRP), a basestation (BS), an eNode B (eNB), a CPE, a UE, a user terminal, a wirelesscommunication system, or some other type of device that supportswireless communication. In various implementations, the device 2000could embody or be implemented within an access terminal, an accesspoint, or some other type of device. In various implementations, thedevice 2000 could embody or be implemented within a server, a personalcomputer, a mobile phone, a smart phone, a tablet, a portable computer,a sensor, an alarm, a vehicle, a machine, an entertainment device, amedical device, or any other electronic device having circuitry. Thedevice 2000 may correspond at least in some aspect to, for example, anyof the BSs (e.g., gNBs) or scheduling entities shown in any of FIGS. 1,2, 4, 5, 6, 7, 15, and 21.

The device 2000 includes a communication interface (e.g., at least onetransceiver) 2002, a storage medium 2004, a user interface 2006, amemory device (e.g., a memory circuit) 2008, and a processing circuit2010 (e.g., at least one processor). In various implementations, theuser interface 2006 may include one or more of a keypad, a display, aspeaker, a microphone, a touchscreen display, of some other circuitryfor receiving an input from or sending an output to a user.

These components can be coupled to and/or placed in electricalcommunication with one another via a signaling bus or other suitablecomponent, represented generally by the connection lines in FIG. 20. Thesignaling bus may include any number of interconnecting buses andbridges depending on the specific application of the processing circuit2010 and the overall design constraints. The signaling bus linkstogether various circuits such that each of the communication interface2002, the storage medium 2004, the user interface 2006, and the memorydevice 2008 are coupled to and/or in electrical communication with theprocessing circuit 2010. The signaling bus may also link various othercircuits (not shown) such as timing sources, peripherals, voltageregulators, and power management circuits, which are well known in theart, and therefore, will not be described any further. In general, thecomponents of FIG. 20 may be similar to corresponding components of theBS 1500 of FIG. 15.

The processing circuit 2010 may be adapted to perform any or all of thefeatures, processes, functions, operations and/or routines for any orall of the devices described herein. For example, the processing circuit2010 may be configured to perform any of the steps, functions, and/orprocesses described with respect to FIGS. 1-11 and 16. As used herein,the term “adapted” in relation to the processing circuit 2010 may referto the processing circuit 2010 being one or more of configured,employed, implemented, and/or programmed to perform a particularprocess, function, operation and/or routine according to variousfeatures described herein.

The processing circuit 2010 may be a specialized processor, such as anapplication-specific integrated circuit (ASIC) that serves as a meansfor (e.g., structure for) carrying out any one of the operationsdescribed in conjunction with FIGS. 1-11 and 16. The processing circuit2010 serves as one example of a means for transmitting and/or a meansfor receiving. In various implementations, the processing circuit 2010may provide and/or incorporate, at least in part, the functionalitydescribed above the first device 702 (e.g., the communication controller706) of FIG. 7.

According to at least one example of the device 2000, the processingcircuit 2010 may include one or more of a circuit/module for determining2020, a circuit/module for generating 2022, or a circuit/module forsending 2024. In various implementations, the circuit/module fordetermining 2020, the circuit/module for generating 2022, or thecircuit/module for sending 2024 may provide and/or incorporate, at leastin part, the functionality described above for the first device 702(e.g., the communication controller 706) of FIG. 7.

As mentioned above, programming stored by the storage medium 2004, whenexecuted by the processing circuit 2010, causes the processing circuit2010 to perform one or more of the various functions and/or processoperations described herein. For example, the programming may cause theprocessing circuit 2010 to perform the various functions, steps, and/orprocesses described herein with respect to FIGS. 1-11 and 16 in variousimplementations. As shown in FIG. 20, the storage medium 2004 mayinclude one or more of code for determining 2040, code for generating2042, or code for sending 2044. In various implementations, the code fordetermining 2040, the code for generating 2042, or the code for sending2044, may be executed or otherwise used to provide the functionalitydescribed herein for the circuit/module for determining 2020, thecircuit/module for generating 2022, or the circuit/module for sending2024.

In some examples, the circuit/module for determining 2020 of FIG. 20(e.g., the handover controller 714 of FIG. 7) performs the operations ofblock 1602 and/or other similar operations as taught herein. In someexamples, the code for determining 2040 of FIG. 20 is executed toperform the operations of block 1602 and/or other similar operations astaught herein.

In some examples, the circuit/module for generating 2022 of FIG. 20(e.g., the communication controller 706 of FIG. 7) performs theoperations of block 1604 and/or other similar operations as taughtherein. In some examples, the code for generating 2042 of FIG. 20 isexecuted to perform the operations of block 1604 and/or other similaroperations as taught herein.

In some examples, the circuit/module for sending 2024 of FIG. 20 (e.g.,the transceiver 708 of FIG. 7) performs the operations of block 1606and/or other similar operations as taught herein. In some examples, thecode for sending 2046 of FIG. 20 is executed to perform the operationsof block 1606 and/or other similar operations as taught herein.

FIG. 21 illustrates a block diagram of an example hardwareimplementation of a wireless communication device 2100 configured tocommunicate according to some aspects. The device 2100 could embody orbe implemented within a base station (BS), a gNB, a transmit receivepoint (TRP), an eNode B (eNB), a CPE, or some other type of device thatsupports wireless communication. In various implementations, the device2100 could embody or be implemented within an access terminal, an accesspoint, or some other type of device. In various implementations, thedevice 2100 could embody or be implemented within a server, a personalcomputer, a mobile phone, a smart phone, a tablet, a portable computer,a sensor, an alarm, a vehicle, a machine, an entertainment device, amedical device, or any other electronic device having circuitry. Thedevice 2100 may correspond at least in some aspect to, for example, anyof the BSs (e.g., gNBs) or scheduling entities shown in any of FIGS. 1,2, 4, 5, 6, 7, 15, and 20.

The device 2100 includes a communication interface 2102 (e.g., at leastone transceiver), a storage medium 2104, a user interface 2106, a memorydevice 2108 (e.g., storing configuration information 2118), and aprocessing circuit 2110 (e.g., at least one processor). In variousimplementations, the user interface 2106 may include one or more of akeypad, a display, a speaker, a microphone, a touchscreen display, ofsome other circuitry for receiving an input from or sending an output toa user. The communication interface 2102 may be coupled to one or moreantennas 2112, and may include a transmitter 2114 and a receiver 2116.In general, the components of FIG. 21 may be similar to correspondingcomponents of the BS 1500 of FIG. 15.

The processing circuit 2110 may be adapted to perform any or all of thefeatures, processes, functions, operations and/or routines for any orall of the devices described herein. For example, the processing circuit2110 may be configured to perform any of the steps, functions, and/orprocesses described with respect to FIGS. 1-11 and 17. As used herein,the term “adapted” in relation to the processing circuit 2110 may referto the processing circuit 2110 being one or more of configured, used,implemented, and/or programmed to perform a particular process,function, operation and/or routine according to various featuresdescribed herein.

The processing circuit 2110 may be a specialized processor, such as anapplication specific integrated circuit (ASIC) that serves as a meansfor (e.g., structure for) carrying out any one of the operationsdescribed in conjunction with FIGS. 1-11 and 17. The processing circuit2110 may serve as one example of a means for transmitting and/or a meansfor receiving. In various implementations, the processing circuit 2110may provide and/or incorporate, at least in part, the functionalitydescribed above for the first device 702 (e.g., the communicationcontroller 706) of FIG. 7.

According to at least one example of the device 2100, the processingcircuit 2110 may include one or more of a circuit/module for determining2120, a circuit/module for generating 2122, or a circuit/module forsending 2124. In various implementations, the circuit/module fordetermining 2120, the circuit/module for generating 2122, or thecircuit/module for sending 2124 may provide and/or incorporate, at leastin part, the functionality described above for the first device 702(e.g., the communication controller 706) of FIG. 7.

As mentioned above, programming stored by the storage medium 2104, whenexecuted by the processing circuit 2110, causes the processing circuit2110 to perform one or more of the various functions and/or processoperations described herein. For example, the programming may cause theprocessing circuit 2110 to perform the various functions, steps, and/orprocesses described herein with respect to FIGS. 1-11 and 17 in variousimplementations. As shown in FIG. 21, the storage medium 2104 mayinclude one or more of code for determining 2140, code for generating2142, or code for sending 2144. In various implementations, the code fordetermining 2140, the code for generating 2142, or the code for sending2144 may be executed or otherwise used to provide the functionalitydescribed herein for the circuit/module for determining 2120, thecircuit/module for generating 2122, or the circuit/module for sending2124.

In some examples, the circuit/module for determining 2120 of FIG. 21(e.g., the handover controller 714 of FIG. 7) performs the operations ofblock 1702 and/or other similar operations as taught herein. In someexamples, the code for determining 2140 of FIG. 21 is executed toperform the operations of block 1702 and/or other similar operations astaught herein.

In some examples, the circuit/module for generating 2122 of FIG. 21(e.g., the communication controller 706 of FIG. 7) performs theoperations of block 1704 and/or other similar operations as taughtherein. In some examples, the code for generating 2142 of FIG. 21 isexecuted to perform the operations of block 1704 and/or other similaroperations as taught herein.

In some examples, the circuit/module for sending 2124 of FIG. 21 (e.g.,the transceiver 708 of FIG. 7) performs the operations of block 1706and/or other similar operations as taught herein. In some examples, thecode for sending 2146 of FIG. 21 is executed to perform the operationsof block 1706 and/or other similar operations as taught herein.

Aspect 1: A method for wireless communication at a wirelesscommunication device, comprising: using a source configuration formaster cell group (MCG) connectivity; receiving a message associatedwith handover of the wireless communication device from the MCGconnectivity to multiple radio access technology-dual connectivity(MR-DC); determining that the message does not include a fullconfiguration indication; and configuring a secondary cell group (SCG)configuration for the MR-DC by reusing the source configuration as aresult of the determining that the message does not include the fullconfiguration indication.

Aspect 2: The method of aspect 1, wherein the SCG configurationcomprises at least one of: a service data adaptation protocol (SDAP)configuration of a data radio bearer (DRB), a packet data convergenceprotocol (PDCP) configuration of a DRB, a physical layer configuration,a medium access control (MAC) layer configuration, a radio link control(RLC) configuration of a DRB, or any combination thereof.

Aspect 3: The method of aspect 1 or 2, further comprising: abstainingfrom reusing a third configuration associated with the MCG connectivityfor the source configuration as a result of the determining that themessage does not include the full configuration indication.

Aspect 4: The method of aspect 3, wherein the third configurationcomprises at least one security configuration.

Aspect 5: The method of any of aspects 1 through 4, wherein the fullconfiguration indication comprises a fullConfig information element(fullConfig IE).

Aspect 6: The method of any of aspects 1 through 5, wherein: the MCGconnectivity is associated with third generation partnership project(3GPP) new radio (NR) connectivity; and the MR-DC is associated with3GPP evolved universal terrestrial radio access (E-UTRA)-NR dualconnectivity (EN-DC).

Aspect 7: The method of any of aspects 1 through 6, wherein: thewireless communication device is served by a third generationpartnership project (3GPP) next-generation-radio access network (NG-RAN)node during the MCG connectivity; and the 3GPP NG-RAN node is associatedwith an SCG for the MR-DC.

Aspect 8: The method of any of aspects 1 through 7, wherein the messageindicates whether a full SCG configuration is provided in the message.

Aspect 9: The method of any of aspects 1 through 8, further comprising:abstaining from reusing at least one security configuration associatedwith the MCG connectivity for the source configuration as a result ofthe determining.

Aspect 10: The method of any of aspects 1 through 9, wherein the messagecomprises a radio resource control (RRC) connection reconfigurationmessage.

Aspect 11: The method of any of aspects 1 through 10, furthercomprising: determining that the message comprises annr-SecondaryCellGroupConfig information element (IE); and applying aconfiguration provided in the IE.

Aspect 13: A method for wireless communication at a wirelesscommunication device, comprising: receiving a message associated withhandover of the wireless communication device from a first connectivitymode to a second connectivity mode, wherein at least one of the firstconnectivity mode or the second connectivity mode is amulti-connectivity mode; determining that the message indicates that thewireless communication device is to reuse a first configurationassociated with the first connectivity mode for the second connectivitymode; and obtaining a second configuration for the second connectivitymode based on the first configuration as a result of the determiningthat the message indicates that the wireless communication device is toreuse the first configuration.

Aspect 14: The method of aspect 13, wherein the multi-connectivity modecomprises a dual-connectivity mode or a multi-radio access technology(multi-RAT) dual-connectivity mode.

Aspect 15: The method of any of aspects 13 through 14, wherein the firstconfiguration comprises a data radio bearer (DRB) configuration.

Aspect 16: The method of any of aspects 13 through 15, furthercomprising: abstaining from reusing a third configuration associatedwith the first connectivity mode for the second configuration as aresult of the determining that the message indicates that the wirelesscommunication device is to reuse the first configuration.

Aspect 17: The method of aspect 16, wherein the third configurationcomprises at least one security configuration.

Aspect 18: The method of any of aspects 13 through 17, wherein: thefirst connectivity mode comprises third generation partnership project(3GPP) new radio (NR) standalone connectivity; the second connectivitymode comprises NR dual connectivity (NR-DC); the first configurationcomprises at least one of: a service data adaptation protocol (SDAP)configuration of a radio bearer (RB), a packet data convergence protocol(PDCP) configuration of an RB, a physical layer configuration, a mediumaccess control (MAC) layer configuration, a radio link control (RLC)configuration of an RB, or any combination thereof; the wirelesscommunication device is served by a 3GPP next-generation-radio accessnetwork (NG-RAN) node during the first connectivity mode; and the 3GPPNG-RAN node is associated with a secondary cell group (SCG) for thesecond connectivity mode.

Aspect 19: The method of any of aspects 13 through 18, wherein: thefirst connectivity mode comprises third generation partnership project(3GPP) long term evolution (LTE) standalone connectivity; the secondconnectivity mode comprises LTE dual connectivity (LTE-DC); the firstconfiguration comprises at least one of: a service data adaptationprotocol (SDAP) configuration of a radio bearer (RB), a packet dataconvergence protocol (PDCP) configuration of an RB, a physical layerconfiguration, a medium access control (MAC) layer configuration, aradio link control (RLC) configuration of an RB, or any combinationthereof; the wireless communication device is served by a 3GPP evolveduniversal terrestrial radio access (E-UTRA) node during the firstconnectivity mode; and the 3GPP E-UTRA node is associated with asecondary cell group (SCG) for the second connectivity mode.

Aspect 20: The method of any of aspects 13 through 19, wherein: thefirst connectivity mode comprises third generation partnership project(3GPP) evolved universal terrestrial radio access (E-UTRA)-NR dualconnectivity (EN-DC); the second connectivity mode comprises NRstandalone connectivity; the first configuration comprises at least oneof: a service data adaptation protocol (SDAP) configuration of a radiobearer (RB), a packet data convergence protocol (PDCP) configuration ofan RB, a physical layer configuration, a medium access control (MAC)layer configuration, a radio link control (RLC) configuration of an RB,or any combination thereof; a secondary cell group (SCG) for the firstconnectivity mode comprises a 3GPP next-generation-radio access network(NG-RAN) node; and the wireless communication device is served by the3GPP NG-RAN node during the second connectivity mode.

Aspect 21: The method of any of aspects 13 through 20, wherein: thefirst connectivity mode comprises third generation partnership project(3GPP) 3GPP) evolved universal terrestrial radio access (E-UTRA)-NR dualconnectivity (EN-DC); the second connectivity mode comprises NR dualconnectivity (NR-DC); the first configuration comprises at least one of:a service data adaptation protocol (SDAP) configuration of a radiobearer (RB), a packet data convergence protocol (PDCP) configuration ofan RB, a physical layer configuration, a medium access control (MAC)layer configuration, a radio link control (RLC) configuration of an RB,or any combination thereof; a secondary cell group (SCG) for the firstconnectivity mode comprises a 3GPP next-generation-radio access network(NG-RAN) node; and the 3GPP NG-RAN node comprises a master cell group(MCG) during the second connectivity mode.

Aspect 22: The method of any of aspects 13 through 21, wherein: thefirst connectivity mode comprises third generation partnership project(3GPP) new radio (NR) connectivity; the second connectivity modecomprises 3GPP evolved universal terrestrial radio access (E-UTRA)-NRdual connectivity (EN-DC); the first configuration comprises at leastone of: a service data adaptation protocol (SDAP) configuration of aradio bearer (RB), a packet data convergence protocol (PDCP)configuration of an RB, a physical layer configuration, a medium accesscontrol (MAC) layer configuration, a radio link control (RLC)configuration of an RB, or any combination thereof; the wirelesscommunication device is served by a 3GPP next-generation-radio accessnetwork (NG-RAN) node during the first connectivity mode; and the 3GPPNG-RAN node is associated with a secondary cell group (SCG) during thesecond connectivity mode.

Aspect 23: The method of any of aspects 13 through 22, wherein themessage comprises an indication of whether a full master cell group(MCG) configuration is provided in the message.

Aspect 24: The method of any of aspects 13 through 23, wherein themessage comprises an indication of whether a full secondary cell group(SCG) configuration is provided in the message.

Aspect 25: The method of any of aspects 13 through 24, wherein themessage comprises a fullConfig information element (fullConfig IE).

Aspect 26: The method of any of aspects 13 through 25, wherein: thefirst connectivity mode comprises a standalone connectivity mode; andthe second connectivity mode comprises a dual connectivity mode.

Aspect 27: The method of any of aspects 13 through 26, wherein: thefirst connectivity mode comprises a dual connectivity mode; and thesecond connectivity mode comprises a standalone connectivity mode.

Aspect 28: The method of any of aspects 13 through 27, wherein: thefirst connectivity mode comprises a first dual connectivity mode; andthe second connectivity mode comprises a second dual connectivity mode.

Aspect 29: The method of any of aspects 13 through 28, wherein: thefirst connectivity mode comprises a first third generation partnershipproject (3GPP) new radio (NR) connectivity mode; and the secondconnectivity mode comprises a second 3GPP NR connectivity mode.

Aspect 30: A wireless communication device comprising: a transceiverconfigured to communicate with a radio access network, a memory, and aprocessor communicatively coupled to the transceiver and the memory,wherein the processor and the memory are configured to perform any oneof aspects 1 through 11.

Aspect 31: An apparatus configured for wireless communication comprisingat least one means for performing any one of aspects 1 through 11.

Aspect 32: A non-transitory computer-readable medium storingcomputer-executable code, comprising code for causing an apparatus toperform any one of aspects 1 through 11.

Aspect 33: A wireless communication device comprising: a transceiverconfigured to communicate with a radio access network, a memory, and aprocessor communicatively coupled to the transceiver and the memory,wherein the processor and the memory are configured to perform any oneof aspects 13 through 29.

Aspect 34: An apparatus configured for wireless communication comprisingat least one means for performing any one of aspects 13 through 29.

Aspect 35: A non-transitory computer-readable medium storingcomputer-executable code, comprising code for causing an apparatus toperform any one of aspects 13 through 29.

Several aspects of a wireless communication network have been presentedwith reference to an example implementation. As those skilled in the artwill readily appreciate, various aspects described throughout thisdisclosure may be extended to other telecommunication systems, networkarchitectures and communication standards.

By way of example, various aspects may be implemented within othersystems defined by 3GPP, such as Long-Term Evolution (LTE), the EvolvedPacket System (EPS), the Universal Mobile Telecommunication System(UMTS), and/or the Global System for Mobile (GSM). Various aspects mayalso be extended to systems defined by the 3rd Generation PartnershipProject 2 (3GPP2), such as CDMA2000 and/or Evolution-Data Optimized(EV-DO). Other examples may be implemented within systems employing IEEE802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Ultra-Wideband (UWB),Bluetooth, and/or other suitable systems. The actual telecommunicationstandard, network architecture, and/or communication standard employedwill depend on the specific application and the overall designconstraints imposed on the system.

Within the present disclosure, the word “exemplary” is used to mean“serving as an example, instance, or illustration.” Any implementationor aspect described herein as “exemplary” is not necessarily to beconstrued as preferred or advantageous over other aspects of thedisclosure. Likewise, the term “aspects” does not require that allaspects of the disclosure include the discussed feature, advantage ormode of operation. The term “coupled” is used herein to refer to thedirect or indirect coupling between two objects. For example, if objectA physically touches object B, and object B touches object C, thenobjects A and C may still be considered coupled to one another—even ifthey do not directly physically touch each other. For instance, a firstobject may be coupled to a second object even though the first object isnever directly physically in contact with the second object. The terms“circuit” and “circuitry” are used broadly, and intended to include bothhardware implementations of electrical devices and conductors that, whenconnected and configured, enable the performance of the functionsdescribed in the present disclosure, without limitation as to the typeof electronic circuits, as well as software implementations ofinformation and instructions that, when executed by a processor, enablethe performance of the functions described in the present disclosure. Asused herein, the term “determining” may encompass a wide variety ofactions. For example, “determining” may include calculating, computing,processing, deriving, investigating, looking up (e.g., looking up in atable, a database or another data structure), ascertaining, resolving,selecting, choosing, establishing, receiving (e.g., receivinginformation), accessing (e.g., accessing data in a memory), and thelike.

One or more of the components, steps, features and/or functionsillustrated in FIGS. 1-21 may be rearranged and/or combined into asingle component, step, feature or function or embodied in severalcomponents, steps, or functions. Additional elements, components, steps,and/or functions may also be added without departing from novel featuresdisclosed herein. The apparatus, devices, and/or components illustratedin FIGS. 1, 2, 4-7, 12, 15, and 18-21 may be configured to perform oneor more of the methods, features, or steps described herein. The novelalgorithms described herein may also be efficiently implemented insoftware and/or embedded in hardware.

It is to be understood that the specific order or hierarchy of steps inthe methods disclosed is an illustration of example processes. Basedupon design preferences, it is understood that the specific order orhierarchy of steps in the methods may be rearranged. The accompanyingmethod claims present elements of the various steps in a sample orderand are not meant to be limited to the specific order or hierarchypresented unless specifically recited therein.

The previous description is provided to enable any person skilled in theart to practice the various aspects described herein. Variousmodifications to these aspects will be readily apparent to those skilledin the art, and the generic principles defined herein may be applied toother aspects. Thus, the claims are not intended to be limited to theaspects shown herein, but are to be accorded the full scope consistentwith the language of the claims, wherein reference to an element in thesingular is not intended to mean “one and only one” unless specificallyso stated, but rather “one or more.” Unless specifically statedotherwise, the term “some” refers to one or more. A phrase referring to“at least one of” a list of items refers to any combination of thoseitems, including single members. As an example, “at least one of: a, b,or c” is intended to cover: a; b; c; a and b; a and c; b and c; and a,b, and c. All structural and functional equivalents to the elements ofthe various aspects described throughout this disclosure that are knownor later come to be known to those of ordinary skill in the art areexpressly incorporated herein by reference and are intended to beencompassed by the claims. Moreover, nothing disclosed herein isintended to be dedicated to the public regardless of whether suchdisclosure is explicitly recited in the claims.

What is claimed is:
 1. A method for wireless communication at a wirelesscommunication device, comprising: using a source configuration formaster cell group (MCG) connectivity; receiving a message associatedwith handover of the wireless communication device from the MCGconnectivity to multiple radio access technology-dual connectivity(MR-DC); determining that the message does not include a fullconfiguration indication; and configuring a secondary cell group (SCG)configuration for the MR-DC by reusing the source configuration as aresult of the determining that the message does not include the fullconfiguration indication.
 2. The method of claim 1, wherein the SCGconfiguration comprises at least one of: a service data adaptationprotocol (SDAP) configuration of a data radio bearer (DRB), a packetdata convergence protocol (PDCP) configuration of a DRB, a physicallayer configuration, a medium access control (MAC) layer configuration,a radio link control (RLC) configuration of a DRB, or any combinationthereof.
 3. The method of claim 1, further comprising: abstaining fromreusing a third configuration associated with the MCG connectivity forthe source configuration as a result of the determining that the messagedoes not include the full configuration indication.
 4. The method ofclaim 3, wherein the third configuration comprises at least one securityconfiguration.
 5. The method of claim 1, wherein the full configurationindication comprises a fullConfig information element (fullConfig IE).6. The method of claim 1, wherein: the MCG connectivity is associatedwith third generation partnership project (3GPP) new radio (NR)connectivity; and the MR-DC is associated with 3GPP evolved universalterrestrial radio access (E-UTRA)-NR dual connectivity (EN-DC).
 7. Themethod of claim 1, wherein: the wireless communication device is servedby a third generation partnership project (3GPP) next-generation-radioaccess network (NG-RAN) node during the MCG connectivity; and the 3GPPNG-RAN node is associated with an SCG for the MR-DC.
 8. The method ofclaim 1, wherein the message indicates whether a full SCG configurationis provided in the message.
 9. A wireless communication device,comprising: a transceiver; a memory; and a processor communicativelycoupled to the transceiver and the memory, wherein the processor and thememory are configured to: use a source configuration for a master cellgroup (MCG) connectivity, receive a message associated with handover ofthe wireless communication device from the MCG connectivity to multipleradio access technology-dual connectivity (MR-DC), determine that themessage does not include a full configuration indication, and configurea secondary cell group (SCG) configuration for the MCG connectivity byreusing the source configuration as a result of the determination thatthe message does not include the full configuration indication.
 10. Thewireless communication device of claim 9, wherein the processor and thememory are further configured to: abstain from reusing at least onesecurity configuration associated with the MCG connectivity for thesource configuration as a result of the determination that the messagedoes not include the full configuration indication.
 11. The wirelesscommunication device of claim 9, wherein: the full configurationindication comprises a fullConfig information element (fullConfig IE);the message comprises a radio resource control (RRC) connectionreconfiguration message; and the message indicates whether a full SCGconfiguration is provided in the message.
 12. The wireless communicationdevice of claim 9, wherein the processor and the memory are furtherconfigured to: determine that the message comprises annr-SecondaryCellGroupConfig information element (IE); and apply aconfiguration provided in the IE.
 13. A method for wirelesscommunication at a wireless communication device, comprising: receivinga message associated with handover of the wireless communication devicefrom a first connectivity mode to a second connectivity mode, wherein atleast one of the first connectivity mode or the second connectivity modeis a multi-connectivity mode; determining that the message indicatesthat the wireless communication device is to reuse a first configurationassociated with the first connectivity mode for the second connectivitymode; and obtaining a second configuration for the second connectivitymode based on the first configuration as a result of the determiningthat the message indicates that the wireless communication device is toreuse the first configuration.
 14. The method of claim 13, wherein themulti-connectivity mode comprises a dual-connectivity mode or amulti-radio access technology (multi-RAT) dual-connectivity mode. 15.The method of claim 13, wherein the first configuration comprises a dataradio bearer (DRB) configuration.
 16. The method of claim 13, furthercomprising: abstaining from reusing a third configuration associatedwith the first connectivity mode for the second configuration as aresult of the determining that the message indicates that the wirelesscommunication device is to reuse the first configuration.
 17. The methodof claim 16, wherein the third configuration comprises at least onesecurity configuration.
 18. The method of claim 13, wherein: the firstconnectivity mode comprises third generation partnership project (3GPP)new radio (NR) standalone connectivity; the second connectivity modecomprises NR dual connectivity (NR-DC); the first configurationcomprises at least one of: a service data adaptation protocol (SDAP)configuration of a radio bearer (RB), a packet data convergence protocol(PDCP) configuration of an RB, a physical layer configuration, a mediumaccess control (MAC) layer configuration, a radio link control (RLC)configuration of an RB, or any combination thereof; the wirelesscommunication device is served by a 3GPP next-generation-radio accessnetwork (NG-RAN) node during the first connectivity mode; and the 3GPPNG-RAN node is associated with a secondary cell group (SCG) for thesecond connectivity mode.
 19. The method of claim 13, wherein: the firstconnectivity mode comprises third generation partnership project (3GPP)long term evolution (LTE) standalone connectivity; the secondconnectivity mode comprises LTE dual connectivity (LTE-DC); the firstconfiguration comprises at least one of: a service data adaptationprotocol (SDAP) configuration of a radio bearer (RB), a packet dataconvergence protocol (PDCP) configuration of an RB, a physical layerconfiguration, a medium access control (MAC) layer configuration, aradio link control (RLC) configuration of an RB, or any combinationthereof; the wireless communication device is served by a 3GPP evolveduniversal terrestrial radio access (E-UTRA) node during the firstconnectivity mode; and the 3GPP E-UTRA node is associated with asecondary cell group (SCG) for the second connectivity mode.
 20. Themethod of claim 13, wherein: the first connectivity mode comprises thirdgeneration partnership project (3GPP) evolved universal terrestrialradio access (E-UTRA)-NR dual connectivity (EN-DC); the secondconnectivity mode comprises NR standalone connectivity; the firstconfiguration comprises at least one of: a service data adaptationprotocol (SDAP) configuration of a radio bearer (RB), a packet dataconvergence protocol (PDCP) configuration of an RB, a physical layerconfiguration, a medium access control (MAC) layer configuration, aradio link control (RLC) configuration of an RB, or any combinationthereof; a secondary cell group (SCG) for the first connectivity modecomprises a 3GPP next-generation-radio access network (NG-RAN) node; andthe wireless communication device is served by the 3GPP NG-RAN nodeduring the second connectivity mode.
 21. The method of claim 13,wherein: the first connectivity mode comprises third generationpartnership project (3GPP) 3GPP) evolved universal terrestrial radioaccess (E-UTRA)-NR dual connectivity (EN-DC); the second connectivitymode comprises NR dual connectivity (NR-DC); the first configurationcomprises at least one of: a service data adaptation protocol (SDAP)configuration of a radio bearer (RB), a packet data convergence protocol(PDCP) configuration of an RB, a physical layer configuration, a mediumaccess control (MAC) layer configuration, a radio link control (RLC)configuration of an RB, or any combination thereof; a secondary cellgroup (SCG) for the first connectivity mode comprises a 3GPPnext-generation-radio access network (NG-RAN) node; and the 3GPP NG-RANnode comprises a master cell group (MCG) during the second connectivitymode.
 22. The method of claim 13, wherein: the first connectivity modecomprises third generation partnership project (3GPP) new radio (NR)connectivity; the second connectivity mode comprises 3GPP evolveduniversal terrestrial radio access (E-UTRA)-NR dual connectivity(EN-DC); the first configuration comprises at least one of: a servicedata adaptation protocol (SDAP) configuration of a radio bearer (RB), apacket data convergence protocol (PDCP) configuration of an RB, aphysical layer configuration, a medium access control (MAC) layerconfiguration, a radio link control (RLC) configuration of an RB, or anycombination thereof; the wireless communication device is served by a3GPP next-generation-radio access network (NG-RAN) node during the firstconnectivity mode; and the 3GPP NG-RAN node is associated with asecondary cell group (SCG) during the second connectivity mode.
 23. Awireless communication device, comprising: a transceiver; a memory; anda processor communicatively coupled to the transceiver and the memory,wherein the processor and the memory are configured to: receive amessage associated with handover of the wireless communication devicefrom a first connectivity mode to a second connectivity mode, wherein atleast one of the first connectivity mode or the second connectivity modeis a multi-connectivity mode; determine that the message indicates thatthe wireless communication device is to reuse a first configurationassociated with the first connectivity mode for the second connectivitymode; and obtain a second configuration for the second connectivity modebased on the first configuration as a result of the determination thatthe message indicates that the wireless communication device is to reusethe first configuration.
 24. The wireless communication device of claim23, wherein the message comprises an indication of whether a full mastercell group (MCG) configuration is provided in the message.
 25. Thewireless communication device of claim 23, wherein the message comprisesan indication of whether a full secondary cell group (SCG) configurationis provided in the message.
 26. The wireless communication device ofclaim 23, wherein the message comprises a fullConfig information element(fullConfig IE).
 27. The wireless communication device of claim 23,wherein: the first connectivity mode comprises a standalone connectivitymode; and the second connectivity mode comprises a dual connectivitymode.
 28. The wireless communication device of claim 23, wherein: thefirst connectivity mode comprises a dual connectivity mode; and thesecond connectivity mode comprises a standalone connectivity mode. 29.The wireless communication device of claim 23, wherein: the firstconnectivity mode comprises a first dual connectivity mode; and thesecond connectivity mode comprises a second dual connectivity mode. 30.The wireless communication device of claim 23, wherein: the firstconnectivity mode comprises a first third generation partnership project(3GPP) new radio (NR) connectivity mode; and the second connectivitymode comprises a second 3GPP NR connectivity mode.